Athletes adapt to what is put in front of them.
Coaches are stuck in their ways of how intelligently they apply stress to their athletes.
If you have a group of athletes who spent several years adapting to X level of stress, and suddenly you put a group of coaches in front of them who won a Pac12 title training with 2X level of stress each week, guess what happens....
Doubly so if you aren't willing/able to see the writing on the wall in terms of your monitoring and adjustments to that level of stress. It hasn't been done in football (presumably because it will make people look bad) but in soccer you can literally see patterns of injury trends follow coaches from team to team as they get fired and re-hired.
The single most powerful person w/ regard to injury in the organisation is the HFC. That individual can negate any other injury mitigation strategy in the organisation.