Since he was the "new kid", I imagine he wanted to remain in George's good graces. And George apparently got the sort of "malleable" director he really wanted. I recall that term from some old article about the film, possibly the original making of paperback?
I'm sincerely glad we're getting to read Marquand's words in all of this. He was barely represented in the Blu Ray extras, and there was plenty of vintage stuff with Kershner. His untimely passing denied us the more candid interviews we've gotten with the other key personnel over the years.