This shouldn’t limit to nimble or savage, but instead to a template. This would keep it future compatible with any new animal companion templates developed later, i.e. sneaky companion, etc.
I find it very annoying that the companion doesn't just advance as the character does. You have to give it commands, it has limited command options, it cannot make use of magic items and you have to keep dumping your feats into it just in the hope of them staying useful.
Took us forever to figure out that the minion trait removed the rule that animals that aren't war trained get frightened 4 and fleeing at the start of combat.
