Help with 3.5 Custom Template

[glitterbaby]

Hey guys! After a hiatus from the game, my group and I are looking at starting up a game again. In particular, I'm looking at playing a dwarf crafter/warrior/ritual caster who rides a boar into battle. Basically, I wanted to play a character who's grasp of magic is academic at best and smashes things up with a hammer from the back of a boar when he needs to get into the nitty-gritty. Sure, he'll have a slew of scrolls to fall back on but he'll primarily be a melee in combat.

Now for the crafter/warrior my DM and I basically worked on making our own ACF of Artificer and we're both happy where that ended up but for the boar I was planning on just having max ranks in Ride and taking the feat Wild Cohort. Unfortunately we're starting at level 1 and you don't get a boar for a while with that feat so my DM said I could try my hand at making a Meager template to apply to a boar to bring it in line with the options I did have and we'd call it good. Now I've tried my hand at making minor changes to classes and brewing up individual feats but I've never really brewed anything like a whole class or a template so I really don't know where to start here.

Oh and for the medium dwarf riding a medium boar, I asked and he said I could just buy a more expensive exotic saddle and call it good. It's a pretty common trope and makes sense so we're not fussing about that too much. We're just trying to keep the numbers in check to make for a nice game all-around.

Thanks a bunch in advance for any and all help y'all offer!

[aimlessPolymath]

Looking over the Boar right now, I see the following major differences between it and, say, a wolf.
Hit points: A Boar has over three times as many effective hit points as a wolf or pony, primarily due to the ferocity ability.
Armor class: A Boar has approximately 2 points more AC.
Accuracy: Slightly higher than a wolf. Fine.
Damage of attacks: Around twice as much as a wolf, primarily due to a much higher Strength. That's one of a a boar's strengths, though.

So:
-Lose the Ferocity ability. Lose one hit die. Hit point total is now 2d8 + 4 = 15, a largeish but reasonable number.
-Lose four points of natural armor, down to +2, in line with other creatures available at level 1. This makes them a "face-tank"- they'll soak attacks with their hit points, not AC. (or Mounted Combat!)
-Lose two points of Strength. Thanks to the magic of rounding, this drops their gore damage to 1d8+1, and their attack bonus to +3.
-Lose the Toughness feat due to losing a level.

That's it.
Note that this isn't exactly a "template", but an adaptation of the boar to a lower level. However, I don't think you could actually template a boar in a fair way! The Ferocity ability grants a huge number of hit points(for level 1) as a static ability, so many that no template I built for the boar would be generally applicable.

A comparison to riding dogs instead (which seem to be the epitome of wild cohorts) would be reasonable justification for not even losing the Strength- they have comparable damage, AC, everything except for hit points (they're CR 1, too).
Actually, if you took riding dogs, renamed their bite to a gore, and traded 4 points of Dex for 2 points of natural armor (a downgrade), you would have the stats of a "lesser boar" pretty well.

[glitterbaby]

My DM and I went through your suggestions are are likely going to use the comparison to the Riding Dog, thank you so much. This has been really helpful!