Therefore it's actually an allegory for a USA which annexed Canada. Celestia and Luna represent class collaborationism, unicorns represent Anglophones, pegasi represent Francophones, earth ponies represent Hispanophones, and all the indigenous nations and vassals and neocolonies and other races are represented by the sapient non-ponies.

I don't know how every other part of MLP:FiM lore fits into this but yeah that's my analysis, I don't make the rules.