The (a) is because I am an idiot and forgot someone else (though it's more of a waiting for the proper spot to have him and then forgetting about it than just glossing over his name like I did with Withey. Anyways), but Sherron Collins is certainly deserving of the 13 spot by himself.
Let's start with the bad: he ended his career on an extremely sour note, going 4-15 with 5 turnovers in KU's 2nd round loss to Northern Iowa in 2010. It's probably fair to say if he got Cole Aldrich, the Morris twins, or Xavier Henry more involved, Kansas probably wins that game and potentially has another Final Four or national title run.
But at the same time it is hard to blame Collins for wanting to shoot his way out of his funk that day. After all, he had bailed the Jayhawks out so many times in 2009 and 2010. Who could forget his epic duel with Willie Warren when Kansas all but sewed up a Big 12 title with a win at Oklahoma. Collins scored 22 points in the 2nd half, including three big threes over the course of four possessions with about 6 minutes left in the game. And how about his huge shot in overtime at K State. Or the fact that Bill Self trusted Collins to be the guy to get the ball to Chalmers when he made his famous shot in 2008.
Beyond those snippets, Collins had back to back high usage years that we haven't seen from a guard at Kansas. He took 30.1 percent of the team's shots while on the floor in his junior year, and while that went down a bit as a senior, he still took around a fourth of the shots. It wasn't just volume, however: Collins shot around 47 percent from two both of those years (as a 5-11 guard, remember) and 37 percent from three both of those years.
As is customary when we get to this part of the list, Collins is all over the KU and Big 12 record books, ranking 21st in Big 12 history in win shares, 14th in points, 15th in field goals made, and 5th in games played. Collins also ranks 3rd all time in Kansas history in threes made, and is 5th in Kansas history in scoring.
Pure points aren't the best way to decide who the best player is, obviously, but 5th all-time in scoring at a place like Kansas is a tremendous accomplishment. He gets knocked down a bit because of his defense, and admittedly the stinker against Northern Iowa still weighs on my mind, but he's one of just two Jayhawks in the modern era (that I can find anyway) to average 20 points and 5 assists per game, and we don't have the streak or the 2008 national title without his heroics.