Hello, I'm very new to the forum, so I say sorry if I do something unappropriate.
I think that one of the most important things for a realistic medieval city is the orography. Medieval fortified cities uses very often mountain place to naturally defende the city from attack. That implies winding roads and different levels of elevation of the city and neighborhoods.
Ok, in the case of this generator tool it can be something very simple, I'm not talking about a 3D model. a scarp to delimitate an area with a different highness can be simple implemented like another line object similar to the walls.
Keep in mind that walls, castles and towers generally arise precisely in correspondence with these elements.
Here are some examples

A quarter on a hill

A castle on a mountain