This is a lesson I wish Tennessee had learned earlier in the season, and it was evident against the first opponent Tennessee played.
Despite having Poole bottled up over and over against Montana, Tennessee continued to run the ball over and over.
However, Bray was able to pass over Montana at will. In my opinion, that means you pass the ball. You don't have to establish the run at the very beginning of the first game. If they can't defend the pass, then just keep passing until they start pulling players from the box. Then you run.
Most teams don't have a balanced defense. They'll be weak against either the run or the pass. When you see that, use what works.
Yes, it would be ideal if Tennessee had a fearsome rushing attack and passing attack, but they didn't. If your run game is weak, then running the ball doesn't help to keep teams honest, it just makes them think they can commit more players to pass coverage and still stop the run.
If you have an unstoppable running back (like Trent Richardson), then there's nothing wrong with giving him 30 touches per game. If you have a fantastic pass attack, there's nothing wrong with running an Air Raid offense.