yea a beast tamer in this sense is a scout class, have birds scout ahead and provide directions, have animals carry your stuff to keep you light and then provide mounts, i mean not having to bother about carrying resources is such a huge boon to a party they must be blind to kick him out, but yea seems like it's not a direct combat class.
and even if he can't provide mounts, just being able to control the horses enough that they run away during a fight and come back afterwards is really valuable since otherwise they risk dying due to stray fireballs & the like.