Oregon's and Frost's offenses have worked even when they haven't had dynamic runners at QB, but they are taken to the next level when they have a dynamic running QB like Mariota. If you look at the QB's Frost has recruited to NU, they are all very dynamic runners. Milton was an effective enough runner to make the offense work at UCF, but Frost can recruit a bigger and better QB to NU, than he can to UCF. Sam McKewon has made some very good points about not needing a QB who can make big plays with his legs against most of NU's schedule, but where a guy like Martinez is most effective is against a defense like Michigan or Wisconsin. A QB who can make a play for himself in the run game is huge against great defenses.