I can't remember having read anything quite as honest on Marquand's role on Jedi, as this, from page 187 in Blueprints, or did I miss something?:
The other new kid on the block was higher up the pecking order, director Richard Marquand, whom Lucas hired to complete the trilogy. Lucas was determined not to experience the gut-wrenching experiences of the first two *Star Wars* films: *Jedi* was going to come in on schedule and on budget, as *Raiders* had. To that end, he replaced Kurtz with producer Howard Kazanjian and promoted Robert Watts to producer; the latter would deal primarily with work in England, and the former would take care of production in the United Sates, were filming would also take place this time around.
In retrospect, it's easy to see that Marquand was the odd man out; nearly everyone else working on the film at that level as an old hand. Early on, because he was under tremendous pressure to move quickly, it was clear that Marguand's dailies were not looking as good as those of *Empire*. Marquand and his DP, Alan Hume, came mainly from television and were lighting *Jedi* equivalently in order to stay on the hectic schedule.
"Richard was more conventional, a charming man, very thorough, and he worked closely with George," says Reynolds. "He was very easy to work with, but a little bit more predictable. I do believe he was a bit intimidated by George, because *Star Wars* and *Empire* were such a huge thing by then."
"George got a little bit worried about the way Richard Marquand was directing it," says Roger Christian, who was brought in unofficially as second unit director. "That was what Robert Watts explained to me, who said, 'Can you come up now and take over second unit? But I can't give you credit, because we promise it to Dave Tomblin.' And I said, 'It doesn't matter to me. I'll help George do anything.' We're family, really. That's how I regarded it. So I arrived–I'll never forget this–I arrived and George said, 'Can you take over?' And Robert said, 'We're under horrendous scheduling problems here. I have to get off these stages and move on, so come with me."