RAW says that animal companions count as travelers, and that every traveler has a job. It also says "Jobs can be performed by PCs, allied NPCs, or NPCs hired for the position." (Jade Regent Players' Guide, pp. 17, 19) So, do animal companions count as allied NPCs?
I'm playing through Jade Regent as a cavalier/samurai, and we had this exact discussion about my mount, the warhorse Akumu. I contended that it should be able to count as a guard, as it's trained for war and better at it than your average level 1 Varisian goon, and my GM agreed, given that it also consumes supplies and takes a "slot" of our caravan. You can see our caravan wagon and staffing disposition in detail in our PDF session summary from when we formed it, pp.12ff.
So ... Does it show I've never actually played Jade Regent.
Having reviewed those pages, I see two options:
- Animal companions are travelers, and the rules only classify travelers three ways, and then categorize jobs based on those three. Your animal companions are part of your party, not hired for the position. And they're not PCs. That leaves allied NPCs as the only classification left. Go with it.
- Since your animal companions are animals, their functionality is limited. You have the option of coming up with a third category and limiting them to be either draft animals (although your companion horse might object) or passengers.
RAW supports one the best, so I'd totally go with that.