What about the Dunmer speaking in an aussie accent? What sense do you make of that?
Well, the Dunmer aren't based on any particular Earth culture the way the Bretons and Redguards and especially the Cyrodilians and Nords are, so I guess they just had to pick an accent and go with it. Isn't there just one Aussie voice actor doing some Dunmer males, though? I don't remember more than that. I think all the rest of the Dunmer men sound American and I wanna say all the Dunmer women have a British accent, but I can't remember offhand. Anyway, only the human races seem to be based off of specific Earth cultures.

More thread necromancy, but anyway, not even all those with African genes on Earth have an accent that comes from 200 years of history in the United States. Why those rules should apply also to fantasy worlds I have no idea.
Because again, the Redguards are, like the other human races, based off of an actual real-world culture to some degree - that of North Africa, to some extent. The Nords are based (loosely) off the real-world Norse, and so they at least attempted to have voice actors use a (possibly pseudo-) Scandinavian accent. Not sure why they made no effort at all to have the Imperials have anything but American accents - an Italian accent would have been interesting.