Although the drunken guards were one of the lines of defense, there were clearly others. Moroni did not feel that he could bypass the drunken guards and safely remove the prisoners. He arranges to have weapons of war delivered to those captives in the city. This suggests that someone was able to scale the wall to get in and to know where to put the weapons, and to warn the Nephite prisoners that weapons were coming and that they should arm themselves and prepare.