For both the game's balance sake, and to add a bit more realism to the game, noble troops should be far less common. I've been seeing anywhere from 1/3-1/2 of troops in villages be noble troops. And given they're all strong troops, I think that's a bit overpowered. I believe switching to a system where you can only recruit nobles of that faction if you're part of that faction, or if you own the town/castle. Could also put limits to how many noble troops you can have, x amount of noble troops created in towns or castles you own. However you do it, less noble troops in the game would be good for balance and more immersive.