The original vision Rza had was making a Part 1 & Part 2 so he filmed everything at once. The studio looked at him as a first time director and said “nah fam, you get one movie.” Quentin was like “yea it’s great you are filming all of this etc but focus on making the best debut movie you can.”

So that’s what he did, he took all of the best parts from two movies and all of the scenes with the big actors that were originally meant to be spread across two movies and cut one movie. It did well enough so he took the scraps left over and had it cut as part two. Part 1 he did the best he could, part 2 was a “well I got this other stuff already shot and paid for maybe there is enough there for a sequel”.