Your detail looks awesome. I've also been struggling with representing cities from a distance. My map has one massive kingdom sized city. I assume realistically it would just look like a gray blob from orbit, but I would find that unsatisfying. I've currently been experimenting with satellite photos of european cities thresholded into black and white then embossed and shrunk way down. I'm not entirely set on the results so far but I think there's some promise in the method.