I would think the MU players would grow very old of not having competitive games and playing only one half of each game. Why can't other coaches use that to their recruiting advantage. UWW is much different in they have competitive games during the regular season and because of where they are located, play against better competition in the playoffs and enjoy having to play competitive games. I think that may well explain why UWW has won so many championships in the recent past.
Someone needs to right a book on the MU program. Hard to believe one school can be so dominant for so long. Hard to believe other D3 schools have not done a case study in an effort to improve their program.
Actually D3 is rife with dynasties. UMU is a good one, but not the most dominant. You'd have to look at Kenyon swimming or the two schools that have dominated wrestling for much longer than UMU let alone UMU/UWW dominated football. Messiah is ridiculously good at soccer, a sport where thanks to low scoring good teams lose to lesser opponents at a much higher rate than sports like football. Some of the women's sports are even worse.
There are always a few things in common among all these dynasties. Institutional will, which includes admissions flexibility and spending money, and excellent coaching. You need both of those, plus a dash of luck to get rolling. Lots of schools have the admissions flexibility but not the money or coaching. Others have the money but not the flexibility. Some have the flexibility and money, but can't find the coaching. Getting all 3, and keeping the coaching, is tricky.
I will say that if you look at the elite D3 football programs they pretty much fall in line. UMU has had all 3, UWW has used football, and athletics in general, as a huge part of their differentiation from the rest of the UWW system. They are an incredible example of institutional will. Linfield and UMHB have spent the money and don't require much admissions flexibility, both let in close to 90% of applicants, as well as excellent coaching. Wesley is somewhat of an outlier. They have the coaching, and the institutional will to get the kids in, but they don't have the facilities indicative of the money. On the other hand, playing as an independent has cost them dearly in travel fees, so now that they have joined a full conference money may be moved from travel to facilities.
There isn't some massive secret here. There is, however, a huge difficulty in getting the right coach and coaching staff. There are lots of good coaches, I think the ODAC has some excellent coaches, but getting to that nationally competitive coach, and assistant coaches, is a big, big mountain. It requires a bit of luck, and then even more than a bit to hold on to that staff.