The OP raises a valid point, but I only really need two names to provide some reassurance that egos will rarely, if ever, be a problem under KO: Ryan Boatright and Omar Calhoun.
Let's start with Omar...here is a kid who was one of the best players in New York City, hit two of the biggest shots of our season a year ago, remained loyal to the program when he had every reason not to be, and oh yeah, was named to the Big East all-freshman team. Yet, a year later, he found himself receiving DNP's in the NCAA Tournament while a grad transfer took all his minutes. Let me ask: did he ever, at any point in the season, second-guess Ollie? Did we ever hear anything about him being a problem in the locker-room? Was he ever anything less than humble and reflective in his dealings with the media? I know for a fact that I would have handled that situation a lot less graciously than he did - after the Michigan State game, he was as genuinely happy as anybody on the team.
Ryan Boatright is as selfless a player as we've had here. I think he was player of the year in Illinois his senior year of high school (and he was in the same recruiting class as Anthony Davis). He scored like 63 points in a high school game one time. As a sophomore, he averaged 15 points per game. And, perhaps most importantly as it relates to this conversation, he's been as candid in expressing his NBA aspirations as any player we've ever had here who has also expressed sentiments of wanting to move his family out of Chicago ASAP. If there was ever a player who had the profile of being unwilling to play second (or third) fiddle, it was him. Instead, he took everything Ollie told him to heart, shot two less times per game during his junior year, and devoted himself to being a distributor/defender during the tournament because that's what we needed him to do. In the national title game, he had everything going - he was sinking his pull-up jumper, nobody on Kentucky could stay in front of him, and he probably could have scored 25 points and become a hero if that was his priority. But do you know how many shots he took in that game? Six. To me, that was the most remarkable stat of the tournament. No other statistic could possibly better represent the collective sacrifice these guys were willing to make.
So, is it nice to have guys who are just happy to be on the team and will wipe sweat off the floor if you ask them to? Of course. And those guys are important. But it's even nicer to have top 100 kids who will channel their talent into whatever means necessary to help the team. As long as guys like Ryan Boatright and Omar Calhoun are around, we won't have teams that drastically underachieve.