The past 3 seasons he hasn't had any shot blockers until Kaufusi came on late last season and BYU had s decent defensive stretch from the SMC game at home to the Gonzaga road win.
His defensive rebounding was no worse than 36th in the country with 6 of 7 top 25 finishes and 3 straight years in the top 10.
But, defensive rebounding has declined too in the past three seasons.
Finally, his beat defenses either limit 3-point attempts or hold the opponents' averages down. That may have been a factor of playing in the MWC, which had its share of good and really bad years of shooting 3s.
On the other hand, The WCC has been the 6th-best, 2nd-best and 11th-best conference in 3-point shooting percentage the past 3 seasons.
You combine trying to defend really good 3-point shooters without a good rim protector and we're just going to struggle - especially when our leading scorer/team leader is just not much of a defensive presence the past three seasons.