BYU played 5 QBs. 2 were injured. One was a situational wildcat QB. The other was so bad in his brief playing time that the field filed a restraining order against him. The 5th was the 3rd best QB on the team. He started every game that Mangum and Hodge did not.
BYU's runningbacks did suffer a lot of injuries number of injuries, but to claim that 8 played because there were tons of injuries misses a few things. Over the past 7 years (and probably longer but I was to lazy to look), BYU played an average of 8 RBs per season.
Squally Canada had 30% of the carries this season. Do you know what % of the team's carries BYU's leading rushers have averaged over the past 7 years? Thats right, 30%. Do you know what % of team carries the Game 1 starter has received over the past 7 years? Only 25%.
Injuries were bad last year and had a very big impact. However they were hardly unprecidented and certainly not insurmountable. That being said, if another season with an unusually high number on injuries occurs, BYU should invest in a new S&C guy.