It just (re)occurred to me, something I wish Total War games would do is to have the traits influence the commanding officers tactics, and that we abolish the command stars.

Instead, we have a rank system, based on the said factions historic ranks, that would determine combat effectiveness of the troops, first and foremost. Second, traits such as "ambusher", "guerrilla", "cavalry commander", "artillery mastermind", "melee specialist" etc, influenced the commanders tactics and which troops the AI decided to give him.

What results is that we know have to face a general with troops he knows how to use in a battle to his favor, with a competent AI. This will force players to think more about how they are committing their forces and with whom.