I read this on a different topic but I figured it needed a new thread -
Quote Originally Posted by HoreTore
If you want to attack a wall, have a seige tower. If you want to run your troops quickly at an undefended section of the wall, get a ladder. It's as simple as that really, you CANNOT attack a defended wall with ladders. It wont work. You'll have to get towers.

BTW, for those of yo who haven't. get the shield fix. Seriously. It makes the game so incredibly much better.