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prototype00
2020-07-03, 11:26 PM
So I've got a Barbarian 5/Rogue X that I'm running in AL focusing on Tankiness and Sneak Attack (took the Sentinel Feat).

I thought it might be fun to have him be bare chested his entire career and to facilitate that, I have him wearing a Belt of Hill Giant Strength so I can concentrate on his Con and Dex. I plan to have him with Max Con and Dex by lvl 15, but the question is what to raise first? Both contribute to AC, but:

Con: HP and Con Saves (but I'm already proficient)
Dex: Lots of Skills (nice to have high stealth for example), Dex Saves (not proficient but I have advantage) and Initiative

What would you max first?

Christew
2020-07-03, 11:58 PM
So I've got a Barbarian 5/Rogue X that I'm running in AL focusing on Tankiness and Sneak Attack (took the Sentinel Feat).

I thought it might be fun to have him be bare chested his entire career and to facilitate that, I have him wearing a Belt of Hill Giant Strength so I can concentrate on his Con and Dex. I plan to have him with Max Con and Dex by lvl 15, but the question is what to raise first? Both contribute to AC, but:

Con: HP and Con Saves (but I'm already proficient)
Dex: Lots of Skills (nice to have high stealth for example), Dex Saves (not proficient but I have advantage) and Initiative

What would you max first?
I mean, it depends on your character goals, but DEX? Ignoring the clear difference in list length, let's unpack:
CON: HP (you have a d12 HD; is +1 HP/lvl really important?) and CON saves (you're proficient and you don't concentrate)
DEX: Skills (versatile), DEX saves (common), Initiative (happens every combat, may have significant impact on rage/surprise)

prototype00
2020-07-04, 12:04 AM
I mean, it depends on your character goals, but DEX? Ignoring the clear difference in list length, let's unpack:
CON: HP (you have a d12 HD; is +1 HP/lvl really important?) and CON saves (you're proficient and you don't concentrate)
DEX: Skills (versatile), DEX saves (common), Initiative (happens every combat, may have significant impact on rage/surprise)

Yeah, after stewing on it a spell, I'm coming to a similar conclusion, but it's good to get good advice too.

Dork_Forge
2020-07-04, 12:26 AM
How many levels into Rogue are you and what are they currently?

Personally I'd go Con because you want to tank and you're losing 2hp per level comparative to a straight Barbarian, but it depends on what your current mods are in my opinion.

prototype00
2020-07-04, 12:41 AM
How many levels into Rogue are you and what are they currently?

Personally I'd go Con because you want to tank and you're losing 2hp per level comparative to a straight Barbarian, but it depends on what your current mods are in my opinion.

Ah, my current spread is 4 Barbarian/Rogue 1. I'm going to pick up my last level of Barb and then go straight Rogue, so I've actually got comparatively good HP for my level (of course I'm a newbie starting T2, so hopefully I'm not the carry for the group, lol).

prototype00

Dork_Forge
2020-07-04, 12:54 AM
Ah, my current spread is 4 Barbarian/Rogue 1. I'm going to pick up my last level of Barb and then go straight Rogue, so I've actually got comparatively good HP for my level (of course I'm a newbie starting T2, so hopefully I'm not the carry for the group, lol).

prototype00

So what are your current modifiers and subclass (and what subclass are you looking at picking up for Rogue?)? Assuming your Dex is at least a 14 I'd probably mix and match them rather than go for one all the way first. Probably alternate them Con/Dex/Con etc.

Edit: I'm currently DMing a similar build at the moment, he's very potent in combat both as a tank and as damage dealer and is having a lot of fun with it (current split Bear totem 6/Swashbuckler 4, Minotaur).

prototype00
2020-07-04, 12:57 AM
So what are your current modifiers and subclass (and what subclass are you looking at picking up for Rogue?)? Assuming your Dex is at least a 14 I'd probably mix and match them rather than go for one all the way first. Probably alternate them Con/Dex/Con etc.

Dex and Con are at 16 (w/o ASI) and Barbarian is Totem Warrior (Bear) and Rogue will probably be Mastermind (something to do with your bonus action that isn't movement or hiding).

Alternating is a good idea, then you wouldn't have any buyers remorse to deal with. If I was to alternate, I'm thinking Dex first, as Con will come in soon-enough ish (and HP is retroactive) and Dex has a wider impact during sessions, but what do you think?

Dork_Forge
2020-07-04, 01:19 AM
Dex and Con are at 16 (w/o ASI) and Barbarian is Totem Warrior (Bear) and Rogue will probably be Mastermind (something to do with your bonus action that isn't movement or hiding).

Alternating is a good idea, then you wouldn't have any buyers remorse to deal with. If I was to alternate, I'm thinking Dex first, as Con will come in soon-enough ish (and HP is retroactive) and Dex has a wider impact during sessions, but what do you think?

That's a good subclass for this kind of thing, you may also wish to consider Inquisitive as it gives you another way of gaining Sneak Attack besides relying on Reckless at times.

Hmm, it depends a bit on your party comp (though you said AL, so I'm guessing the party is inconsisitent at best?), if you're solo tanking then you might find yourself missing the hp if your next Con bump doesn't come until level 13. Overall though you're correct that Dex has the most wide reaching impact of the two stats, alternating the two with Dex first shouldn't really be much of an issue, especially when you get Uncanny Dodge.

prototype00
2020-07-04, 01:24 AM
That's a good subclass for this kind of thing, you may also wish to consider Inquisitive as it gives you another way of gaining Sneak Attack besides relying on Reckless at times.

Hmm, it depends a bit on your party comp (though you said AL, so I'm guessing the party is inconsisitent at best?), if you're solo tanking then you might find yourself missing the hp if your next Con bump doesn't come until level 13. Overall though you're correct that Dex has the most wide reaching impact of the two stats, alternating the two with Dex first shouldn't really be much of an issue, especially when you get Uncanny Dodge.

Ah, I've actually got an ASI (4th lvl Barbarian), and a feat (vHuman), so the next ASI pick will be at lvl 9 (I'm currently lvl 5).

AL is a mad grab-bag of whoever signs up, so its a most generally useful character I'm aiming for.

Dork_Forge
2020-07-04, 01:28 AM
Ah, I've actually got an ASI (4th lvl Barbarian), and a feat (vHuman), so the next ASI pick will be at lvl 9 (I'm currently lvl 5).

AL is a mad grab-bag of whoever signs up, so its a most generally useful character I'm aiming for.

To clarify, the level 13 part was in the context of alternating with the first bump coming up going to Dex.

Mastermind is a solid Rogue subclass for in and out of combat, I'm sure your party will be thankful of your abilities regardless of who turns up on any given night.

diplomancer
2020-07-04, 05:38 AM
Dex. Initiative, stealth, and dex saves are better than hit points. Also, sometimes you don't have a foe in melee range, have a long bow at the ready for such occasions.
Are you going rapier+shield, rapier+grappling, 2 short swords, or short sword + dagger? All 4 are good, but different.

Swashbuckler is the best melee rogue, I believe, you won't HAVE to reckless attack to get your sneak attack, will save you a lot of hit points. You can have Str 8, Dex 16, Con 16, Wis 10, Int 8, Cha 14, for a +2 to initiative as well, you will be going first a lot. Alternatively, 13 wis and 12 cha, get the resilient wisdom feat (a dangerous weakness your character has), I'd probably take it at rogue level 4 or 8. Don't worry about Slippery mind. Even if you reach level 20, the 6th Barbarian level is very decent, specially for the 4th rage. You will probably take it eventually. Both the eagle and tiger totem enhancements are very good.

Thief's fast hands can also be a lot of fun with some creativity. With your magically enhanced str, you can carry a lot of ball bearings and caltrops, for instance.

Finally, try to get a sentinel shield.

If rebuilds are still allowed, I'd switch sentinel for shield master, even more if you can use the bonus action before the attacks, and bearbarian to ancestral guardians. Ancestral guardians is wonderful if you wanna tank.

Edit: I don't know enough about AL rules. CAN you multiclass with Barbarian if your STR comes from a magical item? That might make a difference.

Quietus
2020-07-04, 08:31 AM
Dex. Initiative, stealth, and dex saves are better than hit points. Also, sometimes you don't have a foe in melee range, have a long bow at the ready for such occasions.
Are you going rapier+shield, rapier+grappling, 2 short swords, or short sword + dagger? All 4 are good, but different.

Swashbuckler is the best melee rogue, I believe, you won't HAVE to reckless attack to get your sneak attack, will save you a lot of hit points. You can have Str 8, Dex 16, Con 16, Wis 10, Int 8, Cha 14, for a +2 to initiative as well, you will be going first a lot. Alternatively, 13 wis and 12 cha, get the resilient wisdom feat (a dangerous weakness your character has), I'd probably take it at rogue level 4 or 8. Don't worry about Slippery mind. Even if you reach level 20, the 6th Barbarian level is very decent, specially for the 4th rage. You will probably take it eventually. Both the eagle and tiger totem enhancements are very good.

Thief's fast hands can also be a lot of fun with some creativity. With your magically enhanced str, you can carry a lot of ball bearings and caltrops, for instance.

Finally, try to get a sentinel shield.

If rebuilds are still allowed, I'd switch sentinel for shield master, even more if you can use the bonus action before the attacks, and bearbarian to ancestral guardians. Ancestral guardians is wonderful if you wanna tank.

Edit: I don't know enough about AL rules. CAN you multiclass with Barbarian if your STR comes from a magical item? That might make a difference.

No, multiclassing is not allowed if your str comes from a magical item. And rebuilds are only allowed until you play your first game as a fifth level character.

Shield Master would be fantastic if the character has expertise Athletics. However, Sentinel has a really big advantage - if you're next to a target, their only option is A) attack you, or B) take an opportunity attack. As this character levels up with more Rogue, that means applying more sneak attack damage, which is extremely valuable. Functionally Sentinel pulls double duty on tanking and DPS, while shield master is all about control and defense. For what Prototype is doing, Sentinel is the better pick.

diplomancer
2020-07-04, 08:44 AM
No, multiclassing is not allowed if your str comes from a magical item. And rebuilds are only allowed until you play your first game as a fifth level character.

Shield Master would be fantastic if the character has expertise Athletics. However, Sentinel has a really big advantage - if you're next to a target, their only option is A) attack you, or B) take an opportunity attack. As this character levels up with more Rogue, that means applying more sneak attack damage, which is extremely valuable. Functionally Sentinel pulls double duty on tanking and DPS, while shield master is all about control and defense. For what Prototype is doing, Sentinel is the better pick.

As he's asking about which ASI to take, I suppose he hasn't taken a session yet at 5th level. Ancestral guardian + sentinel is probably still better for tanking than sentinel+totem, unless you're facing a lot of monsters with non weapon damage.
With 13 str requirement, some of the swashbuckler features get wasted. Might be enough to push it to a different subclass. Thief is fun.

Finally, 2 Fighter levels might be better than Rogue 14/15. Something to think about.

Quietus
2020-07-04, 08:52 AM
As he's asking about which ASI to take, I suppose he hasn't taken a session yet at 5th level. Ancestral guardian + shield master (why wouldn't he have athetics expertise as a Rogue/Barbarian? ) is probably better than sentinel+totem.
With 13 str requirement, some of the swashbuckler features get wasted. Might be enough to push it to a different subclass. Thief is fun.

I agree, Thief is a great option. However, Mastermind would also be fun with the bonus action helps. And ancestral guardian + shield master is a lot of fun, I can confirm. However, that is a more dedicaed defensive tank. You stand over one enemy and shut them down. Totem is a fine choice, I'd be wavering between bear and wolf myself - wolf synergizes nicely with sentinel, as now all your friends have advantage in melee, which provides more targets for the opponent, and that opponent has to decide between going after you, or targeting someone more squishy while taking free sneak attacks. Sentinel provides tanking role in the simplest form - try to move, I hit you and you stop. It's less damage mitigation and more removal of target's options. But the big thing as I mentioned before is the ability to apply sneak attack once per turn. That's turn, not round; if someone triggers your sentinel feat, then you get a second sneak attack in the round.

Worth noting is that both of these feats will compete with your normal rogue shenanigans; shield master competes with cunning action, and thief's fast hands/mastermind's help. Sentinel competes with .. is it uncanny dodge? The thing that gives you half damage from one attack.

Anyway. Aside from these, Prototype - between dex and con? I'd choose dex every time.

ThatoneGuy84
2020-07-04, 10:04 AM
Assuming you plan to run some sort of dex based weap for attack for sneak.
Duel wielding or s/b

Standard point buy
13str (mc)
15dex +1 vhum
15con +1 vhum
8int
11wis + 1 feat
9cha

Resiliant - Wisdom feat to shore us wis to 12

Asi at 4 barb Dex
Asi at 4 rouge (lvl 9 for you)- Dex

Then decide if you need the con at that point
2 AC and roughly 2 hp per level is great but honestly might not be that nessisary at that point in the career. Being totem you will be able to eat Dmg pretty soundly already (if bear) you might not decide that that you need 20 Con in the end.

As for subclass, I'm a fan of swashbuckler rouges on melee as alternate ways to sneak without having to reckless (if your boosting AC and recklessing it defeats the purpose to me)

Quietus
2020-07-04, 11:56 AM
Assuming you plan to run some sort of dex based weap for attack for sneak.
Duel wielding or s/b



You just need to be using a finesse weapon, you don't have to attack with dex. So a barb/rogue typically uses a rapier, for a one handed d8 weapon that is finesse, so it qualifies for sneak attack, and then they just use pure strength with it. Hence the gauntlets of strength that the OP mentioned.

Keravath
2020-07-04, 01:57 PM
No, multiclassing is not allowed if your str comes from a magical item. And rebuilds are only allowed until you play your first game as a fifth level character.



Actually. The current AL FAQ 9.1 says the following:

"Multiclass Characters If abandoning an item would render your character ineligible for multi-classing into a class of which they possess a level, you must rebuild your character’s ability scores to qualify for your classes, but can’t change any other aspect of the character."

This implies that it is AL legal to use a magic item to obtain the stat needed to multiclass a character. RAW just says that you require a minimum stat and does NOT explicitly state that this must be a natural stat and not one granted by a magic item.

This citation comes from a section referring to items with persistent effects like a Tome of Clear Thought. However, the specific citation in regards to multiclass characters and items does not specify only a specific type of magic item - it is written in such a way that it refers to any magic item.

So, until the AL admins offer clarification (which I haven't seen but they might have done so - I am not in their facebook group), the way the FAQ is currently written it is AL legal to use magic items to obtain the stats needed for multiclassing. (Someone else pointed this out to me when I asked about it so I thought I would pass it along).

Quietus
2020-07-04, 02:23 PM
Actually. The current AL FAQ 9.1 says the following:

"Multiclass Characters If abandoning an item would render your character ineligible for multi-classing into a class of which they possess a level, you must rebuild your character’s ability scores to qualify for your classes, but can’t change any other aspect of the character."

This implies that it is AL legal to use a magic item to obtain the stat needed to multiclass a character. RAW just says that you require a minimum stat and does NOT explicitly state that this must be a natural stat and not one granted by a magic item.

This citation comes from a section referring to items with persistent effects like a Tome of Clear Thought. However, the specific citation in regards to multiclass characters and items does not specify only a specific type of magic item - it is written in such a way that it refers to any magic item.

So, until the AL admins offer clarification (which I haven't seen but they might have done so - I am not in their facebook group), the way the FAQ is currently written it is AL legal to use magic items to obtain the stats needed for multiclassing. (Someone else pointed this out to me when I asked about it so I thought I would pass it along).

There is Sage Advice clarifying that the intent was that you had to qualify for multiclassing requirements under your own power. I'm part of the FB group, but a quick search didn't show anything in the last year stating one way or another. I would expect table variation, I wouldn't allow a character using an item to qualify for multiclassing because of it, Tomes excepted. I have also put the question on the AL group and will report back if I get a solid answer.

da newt
2020-07-04, 02:30 PM
Keravath - I think your interpretation of the quoted AL rule is off. I THINK it means that you must meet the minimum stat requirement for multiclassing without magic items.

"you must rebuild your character’s ability scores to qualify for your classes" - to me this means you must have the raw stats for the multiclass without magical boosts or you cannot be multiclassed legally in AL.

BUT - if there is more to the quote, I may be wrong. Can you link the FAQ?

prototype00
2020-07-04, 11:33 PM
Dex. Initiative, stealth, and dex saves are better than hit points. Also, sometimes you don't have a foe in melee range, have a long bow at the ready for such occasions.
Are you going rapier+shield, rapier+grappling, 2 short swords, or short sword + dagger? All 4 are good, but different.

Swashbuckler is the best melee rogue, I believe, you won't HAVE to reckless attack to get your sneak attack, will save you a lot of hit points. You can have Str 8, Dex 16, Con 16, Wis 10, Int 8, Cha 14, for a +2 to initiative as well, you will be going first a lot. Alternatively, 13 wis and 12 cha, get the resilient wisdom feat (a dangerous weakness your character has), I'd probably take it at rogue level 4 or 8. Don't worry about Slippery mind. Even if you reach level 20, the 6th Barbarian level is very decent, specially for the 4th rage. You will probably take it eventually. Both the eagle and tiger totem enhancements are very good.

Thief's fast hands can also be a lot of fun with some creativity. With your magically enhanced str, you can carry a lot of ball bearings and caltrops, for instance.

Finally, try to get a sentinel shield.

If rebuilds are still allowed, I'd switch sentinel for shield master, even more if you can use the bonus action before the attacks, and bearbarian to ancestral guardians. Ancestral guardians is wonderful if you wanna tank.

Edit: I don't know enough about AL rules. CAN you multiclass with Barbarian if your STR comes from a magical item? That might make a difference.

I was thinking about Swashbuckler, but for a Sentinel tank build I realized the following things:

1. Getting the mobility like ability to not take AoOs is a bit counter to my move-up-and immobilize tactic with Sentinel, if not immediately anti-synergistic.

2. Sentinel's "if the enemy attacks an ally you get an AOO" would still grant you SA whether you were a Swashbuckler or any other rogue (ally is threatening same enemy).

3. This character is meant to prompt bad choices, do I attack another foe and get SA for a bunch or do I attack this Barb Rogue and do 1/4 damage with Uncanny Dodge, if I even hit at all, the AC is pretty decent? So losing that HP is par for the course, and I plan to do an internal trade for a Cloak of Displacement to make the calculus even worse.

4. Granted there is one scenario where the Swashbuckler is directly better, when the enemy tries to move away and there are no other allies within range. At that point, you do get to SA because the Swashbuckler's alternate SA mode kicks in, but after weighing the pros and cons I figured Mastermind was more what I was looking for (mostly because of MAD, I am unable to boost Charisma super high as well).

Quietus
2020-07-05, 08:32 PM
Actually. The current AL FAQ 9.1 says the following:

"Multiclass Characters If abandoning an item would render your character ineligible for multi-classing into a class of which they possess a level, you must rebuild your character’s ability scores to qualify for your classes, but can’t change any other aspect of the character."

This implies that it is AL legal to use a magic item to obtain the stat needed to multiclass a character. RAW just says that you require a minimum stat and does NOT explicitly state that this must be a natural stat and not one granted by a magic item.

This citation comes from a section referring to items with persistent effects like a Tome of Clear Thought. However, the specific citation in regards to multiclass characters and items does not specify only a specific type of magic item - it is written in such a way that it refers to any magic item.

So, until the AL admins offer clarification (which I haven't seen but they might have done so - I am not in their facebook group), the way the FAQ is currently written it is AL legal to use magic items to obtain the stats needed for multiclassing. (Someone else pointed this out to me when I asked about it so I thought I would pass it along).

As of right now, the admins have not spoken up directly. However, this is included in the Sage Compendium, which should be considered when making rulings for AL :

https://scontent.fybz1-1.fna.fbcdn.net/v/t1.0-9/106466803_10158873684579595_3695835408507005460_o. jpg?_nc_cat=110&_nc_sid=dbeb18&_nc_ohc=0xkKUdB3yFgAX8N_wnx&_nc_ht=scontent.fybz1-1.fna&oh=b10734be93968401f74e7e8f528d4a4a&oe=5F267537

https://scontent.fybz1-1.fna.fbcdn.net/v/t1.0-9/107383116_10157667181422613_6996230455654704726_o. jpg?_nc_cat=105&_nc_sid=dbeb18&_nc_ohc=MejTXCdNtzwAX-fT-uU&_nc_ht=scontent.fybz1-1.fna&oh=25d5e5aa2b9f0668f0d222aa1d60808d&oe=5F29F29C


I believe the quoted text Keravath supplied was specifically with the niche situation in mind of stat-increasing Tomes and the like, which do provide a permanent bump to the stat in question.

Spartan_MD
2020-07-05, 10:26 PM
A few thoughts...

You seem concerned about your bonus action and what to do with it if you’re not taking a cunning action. Wielding two short swords would give you an additional chance to sneak attack instead If you missed the first strike. Also, you’d be able to apply rage bonus damage to both attacks.

I hear a lot of love for swashbucklers, but you won’t be able to take advantage of the bonus to initiative as your charisma is a dump stat. Between reckless or using the standard fare, it shouldn’t be that tough to get a sneak attack. A scout might work better. Unfortunately, there is no thug type rogue in AL.

Bottom line is I’d take constitution.

Sorlock Master
2020-07-06, 02:15 AM
So I've got a Barbarian 5/Rogue X that I'm running in AL focusing on Tankiness and Sneak Attack (took the Sentinel Feat).

I thought it might be fun to have him be bare chested his entire career and to facilitate that, I have him wearing a Belt of Hill Giant Strength so I can concentrate on his Con and Dex. I plan to have him with Max Con and Dex by lvl 15, but the question is what to raise first? Both contribute to AC, but:

Con: HP and Con Saves (but I'm already proficient)
Dex: Lots of Skills (nice to have high stealth for example), Dex Saves (not proficient but I have advantage) and Initiative

What would you max first?

CON if you intend to tank with no armor, getting HP and an Armor bump at the same time is better then a small percentage increase on a few skills.

Not sure why you took Sentinel since your going to get Uncanny Dodge, which will make you a beast of a tank.

What weapons do you intend to use? Sword and board?

prototype00
2020-07-06, 04:14 AM
CON if you intend to tank with no armor, getting HP and an Armor bump at the same time is better then a small percentage increase on a few skills.

Not sure why you took Sentinel since your going to get Uncanny Dodge, which will make you a beast of a tank.

What weapons do you intend to use? Sword and board?

Sentinel is quite synergistic with Uncanny Dodge, actually, for all that they both use Reactions.

1. Enemy hits me, use reaction for uncanny dodge and they do 1/4 damage.

2. Enemy attacks ally close by, use reaction for Sentinel and attack. If hit, trigger SA damage.

3. Enemy tries to disengage away, use reaction for Sentinel and attack. May or may not trigger SA. Enemy stops moving.

The intention is Rapier and Shield, yes. See if I can finagle a +3 Shield later for even more tankiness.

Sorlock Master
2020-07-06, 05:51 AM
So I've got a Barbarian 5/Rogue X that I'm running in AL focusing on Tankiness and Sneak Attack (took the Sentinel Feat).

I thought it might be fun to have him be bare chested his entire career and to facilitate that, I have him wearing a Belt of Hill Giant Strength so I can concentrate on his Con and Dex. I plan to have him with Max Con and Dex by lvl 15, but the question is what to raise first? Both contribute to AC, but:

Con: HP and Con Saves (but I'm already proficient)
Dex: Lots of Skills (nice to have high stealth for example), Dex Saves (not proficient but I have advantage) and Initiative

What would you max first?


Sentinel is quite synergistic with Uncanny Dodge, actually, for all that they both use Reactions.

1. Enemy hits me, use reaction for uncanny dodge and they do 1/4 damage.

2. Enemy attacks ally close by, use reaction for Sentinel and attack. If hit, trigger SA damage.

3. Enemy tries to disengage away, use reaction for Sentinel and attack. May or may not trigger SA. Enemy stops moving.

The intention is Rapier and Shield, yes. See if I can finagle a +3 Shield later for even more tankiness.

That's the problem though with them both using reaction your investing in 2 skills, one a HEAVY investment, which will at best be used half the time.

Giving up a feat which will just compete with another classes feature isn't very efficient.

Also, consider the Thief archtype. Bonus action to use an object can be very useful. Not to mention the added jump distance.

prototype00
2020-07-06, 06:25 AM
That's the problem though with them both using reaction your investing in 2 skills, one a HEAVY investment, which will at best be used half the time.

Giving up a feat which will just compete with another classes feature isn't very efficient.

Also, consider the Thief archtype. Bonus action to use an object can be very useful. Not to mention the added jump distance.

I take it you mean feat (Sentinel) and Class Ability (Uncanny Dodge) and not skills?

As described, whether the enemy attacks me or not, a good use of the Reaction is achieved.

Lets take the alternate interpretation just to probe what you are saying:

1. A fighter with Sentinel and no Uncanny Dodge - If the enemy hits his ally, he gets to respond with an AoO, but if the enemy hits him then he gets no benefit and use with his Reaction.

2. A Rogue with Uncanny Dodge but no Sentinel - If an enemy hits him, he gets to reduce damage with Uncanny Dodge using his Reaction, but if the enemy chooses to hit his friend, he's completely out of luck, no usage of his reaction.

In both those cases, the rogue and the fighter only get to use their Reaction half of the time.

However in the case of the Barbarian/Rogue with Sentinel:

- If the enemy hits him, he gets to Uncanny Dodge
- If the enemy hits a nearby ally, he gets to AoO with added SA damage

Which compared to the previous two examples isn't that 100% good use of Reaction? (Of course if there are multiple foes, you only get one reaction, but thats always been the case).

What is the poor investment that you are trying to point out here?