Maybe the scheme is not the problem, maybe players are not executing the scheme. A lot of pieces have to come together for an offense to click. BYU's O-Line play has been average, RB below average, QB below average, WR average. The only position group that has played above average is tight ends. I don't care what scheme you run, that kind of production will not be effective.
I guess you could argue that Ty is ultimately responsible for making sure that the players do their jobs and play above their ability, but again, that is a different discussion than OC and scheme issues.
Also, don't undersell the LSU or UTah defense. Both are very, very good.