As a Veteran player, I’d say the system could still use a boost, if the devs won’t rein in the number of high end enemies the player faces by the endgame. Fighting outnumbered 2:1 by equal or superior foes just isn’t sustainable and eventually your company’s ground to dust.
How else could we face those odds without constant pyrrhic victories (at best) that leave the company decimated, if not by allowing brothers to become stronger?
It probably shouldn’t be treated like a normal level up, but just a +1 seems too little. Perhaps it could be governed by potential, and allow greater single increases. Just one or two increases per level, but potentially deeper ones.