I’ve long held the belief that Lucas’ real passion for filmmaking was in editing. Just look at how excited he is in the TPM doc about how digital tools let him blend together a performance by actor A from one take and a performance by actor B from another take in the same shot.
Lucas is a great big-picture idea guy, an average writer and director, and a fantastic editor. I also think he would have personally edited every Star Wars movie if his duties as producer and director didn’t make that pretty much impossible.