There's another variant on the fantasy idea, and that's the "alternate history". To some extent all the TW games are alternate histories in the way they diverge from recorded history, but you could take that much further, with a really wild starting scenario.

For example, I read a novel a while back... I can't remember the title, but the premise was that the Black Death was much, much worse than the historical plague. It was so bad it totally depopulated Europe out to the Eastern steppes and down through the Med, wiping out Western civilization. Science and technology was developed by the Muslim nations and the Chinese, and those became the dominant players on the world stage. The Muslim nations occupy an empty Europe, and China colonizes the Americas (it goes against their historical isolationism, but hey, it's a fantasy).

You could have either a M2:TW or Empire:TW period game based on that scenario, with those two great civilizations (and their allies) in conflict, and no traditional European nations at all. Imagine Chinese battle junks duking it out with Arab ships of the line in the Caribbean....