I’ve read the first 4 pages of this thread and one thing that I don’t think was mentioned yet is that the plots of all 3 prequels films are very similar. They always have the main characters together for the first act. In the second act, they split up, and in the 3rd act they come back together. If you you think about it the plots of TPM, AOTC, & ROTS are all very similar. I think this is a common trait of directors, but especially in the case of George Lucas. I think George avoided keeping main characters together for too long because it is easier to write dialogue with strangers than people who know each other. This is why it is good that Disney is having the sequel trilogy written & directed by different people. If the same person makes the films for a film franchise for too long, they get and stale and repetitive as seen with the prequels vs. the OT.
In fairness, ESB was the Star Wars movie with the least input from George and even it split the characters up in the middle.