Currently an archer unit is not allowed to fire at any unit that is "engaged" in combat. This results in these types of units being highly ineffective when the opposing force contains little or no archers as they have no targets for most of any battle. In real life, archers would not just stand around watching their fellows fight and die but would engage with a more careful use of their weapons.
I would suggest that instead of requiring archers to just sit back and watch the battle, that they be allowed to fire into melee with reduced effectiveness due to the care needed to target the "rear" of the enemy units or individual men. This would be most appropriate when the target is a large unit is engaging a small unit. This would allow a more realistic battle.
