I'm surprised that no one has proposed to the devs adding a new feature so that you have the ability to pick & choose what type of fort to build after the game starts. So that you might have a fortified city as your capital, yet be able to build wizard's towers or mausoleums if you so choose. Obviously this would be such a dramatic change, and hard enough to code, that it would likely have to wait for a Dom 3, but still, I am a bit surprised that no one appears to have proposed it. Well, until now.
