If they wanted to do something truly original, they wouldn’t have any Sith at all. Or maybe a Sith that we’re not familiar with, and no Jedi.
That’s why I’m most excited for Mangold’s Dawn of the Jedi film, in the case of doing something original. Technically, it won’t have Jedi in the traditional way, but a small group of people discovering the force and how to wield it seems interesting.