for starters your Ute defense is different than our Cougars. We all know where your loyalties are and I am not sure why you continue the act. Its really old.
Second, BYU's total defense (yards) which is the stat you seem concerned about , average rank is around 45 since Bronco took it over. (That stat takes in this year's rank into account so it could change significantly over the next seven games) Not great but certainly not on the level of stinky defense. Third, Utah's defense ranks 32 and TCU's ranks 26 over the same time period. BYU's defense isn't that far behind those teams and is ahead of the other teams you mentioned.