Michigan doesn't have to get its hands dirty in order to recruit better. Not every high major prospect has a dirty recruitment. Some yes, but there are plenty that don't. JB handcuffs himself with some of his own recruiting policies and still has gotten several top 50 guys. Someone like Mack can easily do better on the recruiting trail.
And what young coaches in the Big Ten are better than Mack? Collins, Pikiell, Miles, Chambers, Groce, and Pitino are all far less accomplished than Mack. Tournament success doesn't really factor in for me. Single elimination tournaments are not really a good evaluative tool IMO.