Quote Originally Posted by Cilia View Post
The only question then is why they have the same naming schemes as our cultures, but asking such questions is not wont to provide answers. Probably not best to dwell on it.
Fanfest lore panel spoilers:
This was answered in the lore panel: they don't. The names the WoD use were names they adopted after coming to our world to blend in. Oda-san and Koji basically confirmed that the shards worlds have developed separately from the Source. They have different cultures, languages, magics/jobs (and presumably history) than our world.