Ok, here's the idea of making H&H look different, much different.
Why not making PCs belong to fraction/nation they want? It can give some skill training discount (for example, arabians can improve sewing faster) and make buildings look different (maybe they can build different buildings, like tents instead of log cabins) and they can make other instruments, for sure. I think it'll force players to come together or to fight more brutally because they'll need other cultures for better working. And yeah, it'll make towns look more interesting and colorful.