Although the answer is McDermott, this is a legit question.
Whether accurately or inaccurately, Daboll will be largely credited with developing Josh Allen and letting those guys get away can be costly.
I live in the D.C.Metropolitan area. I was banging the table for Washington to fire Jay Gruden and promote McVay in 2017. Instead, they fooloshly let McVay get away and ended up firing Gruden 5 games into the 2019 season.
You've seen it time and time again, where maybe the OC should have been promoted and the HC let go. *Maybe. Reich in Philly, but was never going to happen off the back of a Super Bowl victory. Kyle Shanahan in Atlanta. Bill Musgrave in Oakland.
Again, I believe McDermott is the answer here. Josh's talent is so that he can probably make any halfway decent coordinator look good.