I'm of the mindset that an all around scum faction doesn't really suit the play style of Legion.
Now, that leaves out a LOT of models, that people would buy.
So what would I do if I were in charge of Legion development?
Well, let me tell you. I would take any new things learned from developing the clone wars era, that will have a wider variety of miniature types.
Then, while developing the sequel factions, I'd develop a smaller squad based game, using the same model scale and mechanics, that focuses on mercenaries - similar to kill team or mordheim (or countless others) in scope.
Again, same overarching mechanics, but a squad of mini-operatives as it were.