
Towns especially are difficult, because there is usually a guard quite near the prison guard, meaning it'll be 2v1 at the very least. I think it's a bug, because it certainly doesn't make any sense from a realism, continuity or mechanical perspective. Also, when you first enter the place (disguised or otherwise) there may still be a normal amount of enemies before the 'rescue' part of the mission starts. Did you set a fire in the nearby village? If you did, make sure to enter the town or castle in question soon after the fire starts.
