To even attempt to make an argument of your post I suggest:
A breakdown of coaches who played in the NFL by race. I think Harbaugh, Rivera, Vrabel, mularky, Reich, Garrett, Lynn.
That's 8 coaches of teams that played as best I can guess of memory, 1 is black. 8/32 is 1/6 of the league. Of those 1/8 is a minority. 1/8. That's 12.5% of former players are coaching. But, 99% of statistics can be shaped to show anything.
To begin projecting the bar is higher for certain groups is reckless and irresponsible is the only real point to be made.