Are you sure all that armor-piercing stuff wouldn't unbalance the game? It is, after all, a game, not a sim.
This would make almost any ranged unit work against armor. The Ulm is said to be the weakest nation because it only has its troops going for it, and the only thing that supposedly makes them special is their armor.
Also, you wrote up '0 AP' as the damage for short bow. Does that mean that the strength of the shooter is added? Is it added for longbows, too? What about slings?