I think opening another castle could work, behe wont be able to handle keeping 3 or more castles at once, theyre big, not that big. Sides, with more castles you wont know who will attack who or when ._.
one castle will keep the controlling guild on their feet the whole time, knowing that the second they stop their precast all the other guilds will swarm them, or something and..it will just be a king of the hill type thing <_>