Hmm... that's an intriguing idea. I think this involves balancing player agency and the rigidity of your plot. If, say, everyone was one of two roles, then it would be easier to control the events of your story.
You could also have the story with chunks of events tied together by player actions. Maybe some people died off, but the events would stay largely the same... it's something worth looking into as a way of taking the workload off of GMs during the game.
I usually wing it when I'm a GM... hence all the crazy plot points. Case in point, Office :P