Adding another thought to the thread, I don't know if Hullbreaker HM would really work, I can't help but feel that whoever the beastmaster job trainer is, it will take us out in to a really wild area, it wouldn't be about domesticating animals in my opinion, it would be more about going in to the wilderness and turning a wild animal in to a loyal savage companion and taming it that way. If you've played Farcry Primal, it's about feeding an animal and gaining it's trust enough that it becomes loyal to you rather than caging and taming it.
As far as animal selection go, I imagine they would standardize the dps across the board, give every creature the same moves to stop one from being the "best" pet. It will probably be solely beastkin and certain scalekin type enemies as well. Coeurls, wolves, bears, tigers, drakes, and maybe the gorillas. I don't know if they'll let us tame the insect types
