and by the way, how do you get archers into the tower?
I was defending, but the archers were at the bottom.
Or is it necessary to move them there during the battle?
By the way, archers in the tower lose the defense bonus from the walls - ranged units hit them without penalties.
During the archers' turn, just click on the tower (you need to be nearby), and the unit will move up. It's better to do this when morale is high, as moving consumes a turn.