Just a quick opinion feedback regarding the adition of cavalry units in the game.
I belive you are using an incorrect principle.
You are only adding a quick movement melee unit that can also fight unmounted long range combat.
Cavalry never developed melee fights the way you are portraying, where the balance of the fight depends on the amount of kills each side makes during a long melee.
Cavalry is a shock force, not a melee one. Let me see if I can explain:
When cavalry charges home to a unprepared infantry unit, the result should be already determined, the action should be really quick as the infantry will immediately brake and flee with very few cavalry casualties. Most infantry casualties happen with the soldiers trying o escape.
If Infantry manages to keep formation (particularly if it manages to form square or occupy defensive terrain) then cavalry will mostly be incapable of causing many casualties and will retire.
Cav vs Cav is more or less the same thing, no melee where troopers brake formation and fight individual fights exist. Instead one of the sides is invariably caught of guard or out manouvered and decides to flee/retreat in an organized manner. If not, then one of the sides brake formation and that´s where the fights happen and the kill ratio grows.
Any way, its always a result of the shock effect, actions never should take too long in an attrition fight like in long range inf vs inf combat.
Same principle should apply to Infantry melee, but I guess you already know that but choose to keep it for the holliwoodesque effect of the melee fight.
This is a problem that afects all the total war games also (particularly the gunpowder war versions), but its something that the old Talonsoft napoleonic games (Waterloo Napoleon´s last battle, and Austerlitz Napoleon´s gratest visctory) actualy got right. I recomend that you have a look at it and you may get some good ideas on how to improve your games if you search historical accuracy.
I belive that if you manage to develop this realities into the game engine, will will have a much deeper tactical game and a much more realistic exciting and original one as well!