I dont either, they are not good regardless of scheme run or personnel at qb1. However, they are better with a DT at the qb position and the reason for this is purely blocking scheme. I'm not nearly as Xs and Os as guys like traz or sas but I did play some ball and know a playbook and protections. Here's a very basic breakdown of why they are better with a DT:
The typical protection scheme for a run play that involves some type of play action or play fake includes attempting to block all rushing defenders. The play fake is an attempt to hold or freeze the D for a split second until they determine whether it is a run or a pass. Either way, the line is attempting to block anyone coming in.
The typical protection for a run play in mullen's scheme involves allowing an edge defender to come free. In fact, it almost dares them to come and come hard. Instead of the defense holding or freezing for a second to determine run or pass, they may hold or freeze to determine inside or outside run and which player (qb or rb) is going to be the one keeping. If the free rusher is controlled or plays safe, the qb will give and the ball will go to the RB, away from the free rusher. If the rusher commits, the qb will often keep and sidestep the rusher and if the QBs a real threat to run, is usually out to a decent gain. This threat makes the defense respect the run game enough to play a bit more safe instead of simply crashing in and plugging holes when reading run.
The problem is that mullen ran that same protection despite trask not being a threat to run. The entire defense would simply commit to stopping the back on a run play and instead of us daring them to commit, they were daring the qb to keep because they knew him doing so was advantage defense. At worst it would be a couple yards for them and they know it. We can and did offset some of this by running run/pass play action, but the fact remains, when your run game is predicated around letting a free rusher in to key off of, but your outside key is executed by a guy who isn't a threat to run, its going to cause the run game to bog down.