So I've made 2 maps with this tactic.
Mackenzie city map text low res watermarked.jpg
Gloomgarde Caldera map small watermarked.jpg
Basically, you use the Clip Studio Paint concentric rings ruler on a layer, which you duplicate for the roads, the buildings, the walls, any features you want to follow that ring, and set up folders for each different ring position you want if they're offset (so there were like 9 different folders set around a different ruler setup for the one example).
Sounds like yours is just a tiered city so you'll really only need the one duplicated rings for the walls, roads, and buildings.
Then you set up every asset that you need to snap to the circle ruler as a "ribbon" brush. That means your roads, your walls, and your buildings. I made my buildings in block length segments and a mixture of single buildings, so that I could chain them. I then do this on a layer set up with a stroke and after I draw in the round buildings I go through with the eraser and remove the bits I don't like, or draw over them again.
I even once made a short video showing how to set this up.
The only parts you'll have to manually draw are the roads that come out radically from the centre, and you can achieve that direction by clicking, holding down shift, and clicking further away. If you want to curve lines, however, you'll need to deactivate the concentric rings ruler and draw manually. So make sure to do the ringed parts first, since at some point you'll probably have to ditch the ruler.
Note you have to set your brushes to "snap" for them to work with a ruler, not all do this by default, I noticed the erasers often don't snap by default in CSP.
I'm afraid I don't know of any convenient mapping tool ways. This is a "draw it yourself" way and I've put many hours into making the brush sets I used for these maps so I have not released them for free, though I may be willing to sell them, not sure, haven't decided. You don't have to make quite as many house blocks as I did, and I will note, mapping programs work GREAT for making the blocks you set up as a ribbon brush.
You just make them in your program of choice with its easy rooftop tools in chunks of like, 1x5 inches and then when you bring them into Clip Studio Paint you can set that as an asset to use for a brush. Turn it to a grayscale layer if you want to be able to color it, or set it up as you want its colors to look and you can draw directly with the finished art!
Here's the brush settings, and how to convert the brush to grayscale before saving it as a brush that you can open from the brush tip menu.
how to set up ribbon brush.jpg
You could do this technique with a mouse especially if you use Clip Studio Paint vector layers but it would be easier with a graphics tablet.
Hope that helps and if not, maybe someone else has a technique for you, and also, you can hire me to do this technique and make you a map with it too!