How do cultures in Equestria relate to real world cultures?

[Greywander 1]

Howdy all, I've been working on a little project, and need a bit of help.  I'm trying to figure out which cultures those in Equestria correlate to in the real world, as this will help me with expanding the canon and creating content that is consistent with the lore (or, at least, with itself).  Because, you know, there are only so many horse puns that can be used as city names.

 

At the moment, I'm mostly concerned with the three pony tribes as seen in the Hearthswarming Eve episode.  The pegasi are the most obvious, with their Greco-Roman influences, but it's the unicorns I'm having the most trouble pinning down.  I'm also curious about non-pony races like the griffons and diamond dogs.

 

I have my own thoughts on the matter, but I'd be interested in hearing what other people think.