It’s actually a ridiculously simple defense (more simple than a HS defense)

Don’t overthink players
Bend but don’t break
Don’t give up big plays
Things tighten up in the red zone

Now whether it’s the right defense is debatable but what others have stated is probably fair... it keeps BYU in ball games,

I’m not totally against it though I do think it would be helpful to make some adjustments when needed (ie Washington last year)