We can't ignore that he's fired an OC and an ST coach to cover up his own deficiencies, plus lost another OC and DC because they hated him, and is probably on track to fire another ST coach by season's end.
Marv had Walt Corey, Ted Marchibroda, and Bruce DeHaven throughout his entire tenure, pretty much, except that Marchibroda left amicably to be a HC elsewhere.
Be the guy that people want to work for. He's not.