Who has the archer stack right now?

I almost always put archers in a single stack. This way, with equal speed, they can fire first. I also consider the presence of siege weapons to be an important criterion. If there's a ballista, I try to place the archers lower, so that the neutrals reach the ballista first and get a few shots in. If there's a wagon, I almost always put the archers in a single stack. But if there are no siege weapons and the speed is different, then it doesn't really matter. IMHO.