Paladin/Rogue Build Help

[Savage Henry]

So, I'm currently running a stupid fun Tabaxi, paladin 5/rogue 1 multiclass with the mobile feat. Oath of Treachery. My DM also allowed me to make a pair of custom hand claws (basically retextured scimitars that do 1d8 instead of 1d6)

She's super sneaky and acrobatic, with expertise in both.

My question is, I'm planning on going the next 4 levels in rogue to get the next ASI, and I can't settle on a roguish archetype, Arcan Trickster or Assassin.

Assassin fits with her theme, and an instant crit would be stupid damage with holy smite, sneak attack, and Chanel divinity - Poison strike, but I feel it's very situational as it requires getting the drop, and it's basically a 1, possible 2 and done. (Would surprise only include the FIRST person I attack during the surprise round, or everyone during the surprise round?)

Arcane trickster would provide more spell slots for holy smite, but I'm not sure if it'd be a better pick.

What do you guys think, or would there be an even better archetype to pick for a sneeeky smiting cat rogue?

[sayaijin]

I would talk with your DM about their use of surprise and the assassin. Sounds like you have a couple levels before it's an issue.

Basically, the rules for surprise are tricky, and many DMs handle them differently. That combined with the fact that assassin requires them to recalculate encounters based on whether or not you land your assassinate ability means that taking the subclass would be a lot of work for both of you.

Also, does your party allow you to sneak ahead so you can actually take advantage of surprise?

Arcane trickster has a lot more versatility, but it sounds like assassin would be more thematic for your class.

[Stangler]

Arcane Trickster all the way. You will have more spell options like shield, shadowblade, mirror image that can help you in melee. You will have things like mage hand and illusion magic to help out of combat. Find familiar for scouting. Rolling big damage numbers once in awhile can be really fun but the AT offers more to the playing experience pretty much all the time and in encounter after encounter.

The only real issue is MAD but you don't need high INT as an AT, it just makes certain spells less attractive.