Archers are a little funky in this game since they start as a ranged unit but eventually upgrade to a melee unit. The attack promotions for archers (barrage and accuracy) are for ranged strength. When they switch from ranged to melee they keep their previous promotions but does it actually help them in combat? I don't think it does and that's kinda weak. If you have a highly upgraded archer what promotions do you usually give them? In the last game I played I gave a couple of them indirect fire which lets them shoot over obsticles. It was nice because the area I was fighting in was heavily forrested. Then again, its kind of a wasted promotion since shortly after that I teched Rifling. They are a powerful class of units but since they change to melee it inhibits some of their abilities in the late game in my opinion. I found I wasn't upgrading some of crossbowman because it was more beneficial to keep them as a ranged unit. I think logistics is a lot more powerful on a ranged unit since it doesn't lose hit points when it attacks.