PB, do you do traits? Simple ones (without triggers).
I've some ideas for general racial traits, for example:
Silvan Elf: +1 command when commanding archers, +1 command when ambushing,
increased chance of recovering casualties (elves heal faster and endure wounds/disease better)
High Elf: +1 command (capable warriors and leaders in general), +1 troop morale (high elven spirit),
increased chance of recovering casualties
Orc: +1 command when attacking (aggressive), +1 command for night battles, X% bonus to looting
Uruk: +1 command when commanding infantry (uruks are better organized and more infantry based), +1 troop morale (uruks are more zealous, more eager to fight, not as likely to run), +1 for night battles
Rohirrim: +2 command when commanding cavalry (obvious), +X% to movement points (mobile largely mounted armies, even foot infantry can ride to battle and then dismount, Rohirrim have enough horses to acommodate this). No third bonus due to +2 to cav command.
Dwarves: +2 siege command, bonus mining income, X% discount on buildings (prolly 10%) I know what I said about rohirrim but sieges are rarer.
Gondor: +1 infantry command (infantry based faction), +1 command when defending (defense/tank oriented faction) + 5% or more to law (again they are disciplined, defensive, provinces are loyal)
You know things like that.

There could be penalities too.