If you’re reading the Rhum Supplements, you’ll read that each sector is 1,000’x1,000’. That makes the city more than five square miles inside the wall. With 40,000 people, that puts the population density somewhere around that of a modern suburb - a nice suburb. That was never the point. The density I’m finding for ancient London and historic Paris are both pretty close to 87,000 per square mile. Let’s remember that London burned because of its narrow streets, and how many plagues did Paris have due to its overcrowding?
So the answer should be somewhere in the middle! We’re ret-conning all the Rhum supplements. Each sector will now be 500’x500’. That brings the size of the city down to one and a third square miles and the population density up to about 30K per sq. mile. That’s about the density of NY or double the density of some of the parts of Chicago I lived in. That makes sense - All I have to do is half the size of the houses that a family of 4.3 lives in, and shrink the streets a bit. Hey some of them can still have gardens, just not big ones. I’m a lot happier with this!
Look for the City of Rhum, the base upon which you can hang the modules, some time when the weather gets warmer.