For me it's a toss up but I'd say mcvay. He has done a decent job but has also blessed with a ton of talent on the team. His in game decisions are questionable. All playoffs he has thrown more than needed because he outsmarts himself. But that's just me.
I'd guess if they ran anderson and Gurley every play they could have mustered more than 3 points and their QB wouldnt have gotten killed.