re: Mid majors with mature, white rosters are crushing it

So true. As George Allen said once, there is no substitute for experience. The reason these mid major teams aren't regarded higher is the conferences they play in...who have experienced veterans starting as well.
SDSU started 4 seniors last year and replaced them this year in the starting lineup with 3. Duke, UK, UNC used to dominate basketball because they had veterans starting, Now, they are lucky if they have a junior in the starting 5. A team is exactly that. A group of guys accustomed to playing with each other and know their assignments.