Heavy axemen get well built so they are always the chunkiest bros around with that +5 hp Heroic linebreaker get wood chopper, really drive home that they walk up to wreck shieldwalls with +40% damage to shields They would only get the personal effects of feats, since they aren't leading anything or the like
I'm a very casual bannerlord player but I have a big interest when it comes to game design and I had a moment of inspiration: What if you gave all t5 troops, a 25 perk from one of the skills to add some flavor and really set them apart from similar troops.