As with other recreations of actual locations I have attempted, getting the physical layout/geometry to match the artists perception is sometimes the biggest challenge. I've resigned myself to roughing in the buildings based on historical data (maps, etc.), adjusting the camera position and details (trying to stay close to typical human focal lengths) and then adjusting reality to match the artist's reality. I've found that insisting the artist always match reality is a recipe for endless frustration. :) I'm diligently trying to follow my Lessons I Wish I Would Learn, specifically Rule #6, and work big to small. My normal tendency is to create some fairly detailed architectural columns and begin populating the scene, beginning in the foreground and working away from the camera. So far, I've been able to use rough blocking with the intention of increasing detail in several waves, once the entire scene is blocked.