Most coaches (especially young ones) will be defined by the kind of staff they surround themselves with.
I know little of the assistants Capel or Kruger hired, but from a Mizzou perspective, I definitely can say assistant coaches can make or break an era.
Norm had some great assistants on his best teams. He knew how to balance quality coaches with quality recruiters, but he never did manage to find assistants who were great with both (see: Norm's nonexistant coaching tree; Bob Sundvold had a brief stint as the head coach at UMKC, Kim Anderson has had success at the DII level (two final fours), and Larry Drew, a Norm player, is an NBA head coach, but that's it).
Quin struggled to build a quality staff, and it cost him (he had one good assistant, and he was only on staff for Quin's first season: John Hammond, who I believe is the current Bucks GM). Probably his second best assistant, Jerry Meyer, contributed to both MU's and Kelvin Sampson's (at Indiana) NCAA trouble.
Anderson had a staff that included his nephew and Melvin freakin' Watkins (plus Matt Zimmerman, who was good). Same staff he has now at Arkansas. They do what he tells them to. Yes-men get you results when every other piece fits perfectly. They did for Mizzou for one season, but before and after, things were always a little messy.
Haith seems to understand the importance of finding good people to surround him. Unlike Anderson, he doesn't just hire guys to parrot back what he wants to hear. In the two years Haith's been at Mizzou, he's had three guys leave for other jobs. Sucks to lose people, but it's nice to know that your head coach can identify coaches that other programs covet (see: Krzyzewski, Self, or Snyder and Stoops in football).
I realize many of you stopped reading 273 words ago after "from a Mizzou perspective" (yes, there were exactly 273 words between perspective and this paragraph). Don't really care. For the college basketball fans who care about more than just OU, I appreciate your willingness to discuss this topic, which affects all programs, and also for your willingness to allow me to indulge myself for a moment on a drunken Friday night.
So much of what goes into building a successful program is unseen by casual fans, but those things — the assistants, the player development, the roster building beyond just recruiting stars — are by far the most interesting. I love watching programs develop from nothing (Butler, VCU for example), rebuild from ashes (OU, MU) or even maintain excellence over decades (Krzyzewski... but not kansas). But no matter the program, it always comes back to the things most people don't see.