Due to this type of defense BYU will almost always play up or down to the level of competition. Their margin of victory against inferior teams will be smaller than anticipated. But the score in losses to better teams will also be closer than expected.
The downside is that games like Saturday's loss against Boise St can happen if the offense has a bunch of turnovers because the margin for error is smaller.
Evidence? If BYU is, in fact, a top 20 team, you would expect them to beat a terrible Arizona team by more than 8 points. You would also expect to put USU away earlier in the game. And you would certainly expect BYU to score more points against BSU, even with all the TOs, than 17 points. But on the plus side, the strategy seemed to work well against a very good Arizona St team. BYU's defensive style game the Sun Devils fewer possessions, and when they made a bunch of mistakes BYU benefitted.
Frankly, I'm sure ASU fans feel pretty much the same about their loss to BYU as we feel about the loss to BSU. But in both cases, the defensive philosophy was a significant contributing factor to the outcome.