This article is based on a discussion between the above mentioned persons on the Direwolf mailing list on what a Skaven Castle should look like and how the Skaven would Defend it.

Frenzied models are a bit problematic in Siege. They must charge if they can and they must always pursue. But they are at the same time standing on top of a wall and defending a castle. Troops on the ramparts do not need to pursue and do not need to charge units that are outside the castle, a unit inside the walls must be charged. Troops in the broken ground, trenchsystem and tunnelsystem must pursue a broken unit. If they are standing behind a defended obstacle they will charge over it. Troops in the ambushholes must charge enemies within their charge range.