Originally Posted by Quillan
You lose far, far more men to the towers than the wall defenders. The missiles fired from the towers are high attack rating (comparable to crossbows, if I remember correctly), armor piercing, and strike from the side or rear most of the time so you don't get your shield against it. Try a test sometime in a campaign battle. Save the game before the battle. Send up a unit of dismounted knights onto a wall section defended by something like the peasant archers you mentioned, and count the casualties. Then reload the game from before the battle and replay it, but this time destroy the towers with artillery before sending the knights up, and see how much of a difference there is.