Something that I have never thought of before was that each region seems to represent a different real life culture. Johto, for instance, has lots of things (Buildings, names, music, etc.) that seem to be a lot like the Japanese culture. Have you ever noticed that? And if so, what culture do you think each region represents?
For me, I think that they go like this:
Kanto- American (A little before or after the Revolutionary War)
Hoenn- South American
This is all personal opinion.