Like Stirk and Anvil are very similar in design, yet feel different, all other regions will have settlements with its own feel, this said only a city has a different tileset, if so, and the poorer the area the more universal it will be, like a shack is a shack everywhere, though even that might be different in Nibenay for example.
In short there are not really a set of rules, it is more how limited we are by time, and modding power
. As the concepts of each of these tilesets are very well thought through and discussed, so that it looks good, but also is very functional for modding.
We rather focus on region by region than take the concepts further in any other region, so nothing can be said about regions other than Gold Coast, other than the regional concepts itself, if made at all, or of all.
The cities of GC are now in concept and planning while the exterior is only partially finished, so I believe it will be hard to get a good answer on detailed questions about regions other than Stirk or Gold Coast.