Yards per attempt matters, but ignoring completion percentage is reckless. A 50% passer over 15 yards is just a punt if he can't sustain drives. LSU's offense thrives on explosive plays AND efficiency, not one at the expense of the other.
Your red zone argument is valid, but a sub-60% rate isn't a death sentence if your defense creates turnovers. LSU's defense forced 22 last year, which covers a lot of offensive sins.