The generator could swep up the data and pick the right "pieces" of buildings, still you probably need to create all the pieces of buildings somehow. So, probably doing a heck of a lot of modelling and try to fit it in somehow + a way to do different LODs. OR a "on-the-fly" modellig program, that would create an building out of picture-data + trying to fill all holes somehow fitting the building footprint ...
... that "stilistic narrative" or "visual appearance trails" is an interesting idea. Having an database of such trails would be an interesting thng to geologically enhance even simpler gity generators to locations and countryes.
Id say, having a simple generator keeping an appearence trail and the foundation blueprint AND having the ability to add specific costum-build buildings to the scene instead of some of them is the best way for the time being.
Also, not sure of what a tremendous effort it would take to do a complex city generator, but i dont think OTs guys have such a deep idea of theyr own city generator, nor the manpower n funding to try doing such a thing. But it might be interlinked somehow, that you could show up the place of the building in OT world and the street-view of it ( a faint transparent projection of the streetviews 360 image in the correct position in OT so you could see the OT world and its generators simpleton city thing, layered upon themselves and look around in 360 degree around ) ? I can imagine that being interesting.
