Let me explain. So, while there's five civ types (dwarf fort, human city, goblin tower, kobold cave, elf forest) there's still ways to configure them differently to get results which let them be visually distinct from one another. I'll start with dwarf sites and the styles I've discovered.
Configuration 1: Default vanilla, they'll build all three dwarf site types (fort, hall, hillock).
Configuration 2: Single Fortress. If you set the starting biome to a specific non-mountain biome, and then set the biome support to a single biome, the civ will only make one fortress, and every other site will be hillocks.
Configuration 3: Road Network. If you set the start biome to ANY_LAND, and settleable biomes to ANY_LAND, what will happen is that the civ will spawn forts in such a way that each fort is spread apart from the next, usually connected by roads, and with around 4 or less hamlets adjacent to each fort.
Configuration 4: Single-Site. Setting the start biome to be EXCLUSIVE_START_BIOME: any land and having BIOME_SUPPORT be ANY_LAND will cause the civ to only spawn a single fortress and never expand.
Basically, I'm curious about other memorable and visually-distinct-on-the-world-map styles of civ-site spread you may have discovered, any are appreciated and this will probably be useful to various modders.