How about the coaching of the players in front of the QB?
You mean the 7th round draft choice at LT. Or the center who went undrafted along with his college teammate at RG from Notre Dame. Or Rashad Coward who was a collegiate DE and converted to RT and was put in at RG. RT has been manned by FAs for the last 5 years.
The only top draft choices have been Whitehair and Daniels and Daniels missed most of the season.
Good coaching can make a difference until it can't.