Well then I think you're just overrating the importance of the YEC on both sides. I agree they are prestigious events, and the pts given show that. But it's different from a normal "tournament", which makes it hard for me to place too much importance on them when rating players. Injuries usually pile up at the end of the year, which makes it hard for every player to give their best effort at the YEC. They're slightly, just slightly above a MS title, but it's hard for me to put them close to the level of a slam and elevate one player over another due to YEC titles.
Sharapova is still ahead of Clijsters to me, because a slam is a slam, and everything else is a level below. 2 slams to 1 for Sharapova. The MS and YEC should only be used when players are tied in the slam count, to me, unless there's a fluke 1 time slam winner, which Sharapova certainly isnt.
Also, look @ who each beat in their slam finals. Clijsters beat Mary Pierce, while Sharapova beat Henin, the other great HC besides Serena, and Ivanovic, who was playing good tennis at the time before her eventual downfall. She also wiped out Henin en route to that AO title in 08. So to me, there's no way you put Clijsters over Sharapova based on the slam results.