That’s another hypothetical scenario. What you did in your idea was focus on what Scorsese presumably did without demonstrating how a Native American filmmaker might have gone about producing the film. It’s possible to do it with smaller scale independent funding, while the distribution might be limited, at least in its intial run. Though talent is talent and Hollywood finances talent. So take a talented Native American filmmaker, the producers they have working with them, they can make a Hollywood film. Regarding rewrites, how could you make a film about that subject if it was just about white saviors? You wouldn't have the opposition. No Osage->no invaders->no saviors. No story.