Coach Smith vs Coach K:
Coach Smith was not only an innovating coach, whose game schematics caused the rules of the game to be changed in a huge way (shot clock), but he was also a tremendous person.
http://www.espn.com/mens-college-ba...ina-coach-dean-smith-was-champion-integration
https://abcnews.go.com/Sports/dean-smith-fought-integration/story?id=28815822
Beyond the normal sort of charity work that any coach does, and his military service (which Smith also had), I'm not aware of any similar stores from coach K.
Coach Williams vs Coach K:
As others have pointed, Dook has completely embraced the one and done model in a way that UNC has not (yes, UNC has the occasional one and done player, but Dook stocks their roster with them). This is counter to how I believe college athletics should operate. If you don't want to be in college, don't go to college; until the NBA changes their rules, go play overseas.