Add a Ranged unit building, like archers, they have light armour and could be a all rounder unit, fast 'reload' times good for attack and then arbalisters have slow reloading time (defensive troops with heavy armour also ) as they take cover behind walls to reload and fire again :D PLZ this game is amazing with cav units and infantry units but no archer units.
 "Realm of Empires: Warlords Rising"){kind=icon}