It's very concerning, and doesn't seem coincidental, that none of these K acolytes has shown conclusive signs of being able to coach defense at a high level in today's game.
Collins comes the closest, by getting one of the least talented power conference teams to play top 100 defense in four of his five seasons. However, his best seasons were #23 and #32 defensively, and this season is a big step back. We can assume he'll do better with much better talent, which would come naturally at Duke (or really just about any other power conference team that's not Northwestern), but that assumption is getting weaker and weaker with each passing season of bad defense by Duke's elite talent.
Wojo's history as a defensive coach at Marquette is awful. Buzz Wililams had them in the 40-60 range consistently. Wojo took over and they slipped to #69, worse than any season under Buzz, and the worst at Marquette in 9 years, dating back to the Tom Crean days. The Marquette defense got progressively and rapidly worse under Wojo, from 69 to 88 to 165, and is sitting at 162 this season. This is not good at all for Duke fans hoping Wojo can be a viable candidate to come in and improve Duke's defense while maintaining the offense.
Brey's best defenses at Notre Dame have been in the 40-60 range, and the defense has slipped to 100 or worse 6 seasons out of 17 in Kenpom. His talent has been better than either Collins or Wojo's talent, in the aggregate, though I'd expect Marquette to have talent down the rotation on par with Notre Dame in the near future.
Amaker hasn't been a bad defensive coach, and given the relative talent level of his teams, I would say he has the best defensive history of all these guys. However, I don't think he'll be given any serious consideration, for plenty of other reasons, so I'll leave out the numbers.
Hurley has the least known defensive track record out of these guys, which is a good thing for him, because what we know so far is not great. What he did at Buffalo was borderline miraculous, but now he has had three bad-to-terrible defensive teams at Arizona State. We'll be able to conclude that he is also a bad defensive coach once he has a full roster of his players in 1-2 seasons.
It seems that any coach who learned from K is likely to be behind the curve on defense now, and both common sense and objective evidence would bear this out. Dawkins is arguably an exception, as he did fairly well at Stanford on defense and is doing exceptionally well at UCF now. Unfortunately, he's 54 years old.