The run game doesn't function without the O line and it wasn't like there were gaping holes in the line that the RBs just missed. They were getting hit in the backfield. The same could be said for the passing game. Carr's mental clock was thrown off most of the season due to the failures of the O line which only got better when Penning, and again much later, Ramczyk weren't playing. That is an O line problem and for some reason Marrone is still employed.