You are right Maia wouldn't toss GSP around like that. But you have to ask why he was able to do that when Chael is a real good wrestler none the less?
My reason is because Chael isn't going for a TD or going forward. He was afraid to to death to be on the ground. So weakly clinched. He probably thought Maia was going to pull guard. That TD is more or less a matter of Chael not being ready for it and sucking so bad on the ground.
GSP would never get tossed like that because in a clinch he would be dropping down for a TD. He isn't as afraid. Who knows though, in that same scenario perahps GSP would get tossed. He hasn't fought a guy like Maia was back then...a guy looking for subs and one of the best at doing it from his back and all areas. BJ was a top guy. Shields was a top guy and more a position wrestler/BJJ. Condit was never going to pull guard or do anything too nuts. When you are in the clinch as a wrestler and are hesitant to use your bread and butter for fear of the ground...you tend to get owned.
1 time getting taken down like that vs. an odd fighter like Maia shouldn't automatically mean he isn't an elite wrestler.