I love CMC, but as you said the running back doesn't matter with a crap OL. Calling our OL crap is a huge understatement. I don't understand why we don't invest in OL, it was a major factor in Cam's injuries and here we're seeing it again.
Skill players are useless when you can't win the battle at the line of scrimmage. The games are won and lost in the trenches.