That would be quite an impressive game. Each simulation would need to be automateable in case the player does not want to manage that particular aspect of the game. Otherwise the game will fall into the trap of "trying to please everyone pleases no one".
Anyways, I'm working on Archapolis, a city builder game. The game will feature more hands on management than existing games in the genre, such as being able to design/build your own buildings. The player will see the interior of the buildings so making the exterior pretty wont need to be worried about. I'm also aiming to have a city board that will automate parts of the game for you if you choose (like having a fire marshall to handle fires)
I've got a tech demo of the path finding code up on youtube here, in case you're interested in path finding hundreds of thousands of units efficiently