F50
Sergeant
Some map-defined points to help the AI with pathfinding would help in certain sieges. Grundwalder castle is a particularly good example of this. Left to itself, the AI will attempt to scale a sheer cliff, which, despite the great climbing skills of horses and infantry, they more often than not, fail to climb (the arrows the enemy pelts them with doesn't help much either). This particular map requires the player (and his troops) to go up a piece of terrain of similar properties to a ladder.