Yeah I can totally see how this makes sense for lots of potential follower types, and I really like that aspect of hostility between natural enemies, I mainly refer specifically to "dumb" tamed animals like donkeys, which ideally work out as a special case since they're seen as animals, after all, essentially under the direct control of the owner and should probably both behave and be treated accordingly.
As for other types of followers like mercenaries, I would imagine you'd simply have to leave them out regardless of and coercion... A menu for control over groups would be nice, I'm sure. I've avoided groups of course due to the original intragroup hostilities, but probably will have to try groups again now that that's been addressed.
My current Zurite caster is pretty awesome, I've been leaning into magic and charisma...