I don't see your image, but I think I understand what you are asking about (something like this?). Currently the closest thing you can get is a city without city walls, but with a shanty town, which can grow around the citadel. Being able to generate a city with a citadel inside city walls is a popular request, so eventually it will be implemented.
Viewing post in Citadel Centric Cities?
Hello Watabou, First of all thank you for MFCG which is a wonderful tool for our D&D adventures. I'm looking for exactly that kind of city. Is there a way for us to use this version of the generator? Today, I use the warp option and Inkscape to edit SVG files but i must admit that it takes a long time.