Kersh was given final cut and Lucas had promised him it would be his movie. He went back on that with the Special Edition. Lucas made a similar promise to Marquand. But he was more amenable because he felt it was Lucas universe and he ought to make the film the way Lucas wanted. Of course he wasn’t alive to object to ROTJ Special Edition, but i doubt he would have minded. You are a director for hire when hired by Lucas, Lucas is the auteur. The only exception if Indiana Jones where it was co partnership with Spielberg, but it was never a suggestion that Lucas was backseat directing those, well at least the first 3, film 4 is arguable.