How did the rematch not prove that Cain was the vastly superior fighter? He beat him literally everywhere the fight took place. JDS had nothing for him. Fight one proved what happens when you fight timidly on the outside with a guy who hits like a mach truck. But when does Cain ever fight like that outside of that one time? Cain is rightfully a huge favorite going into this one. JDS fans are delightfully delusional since they are expecting Cain to come in injured again waiting for JDS to clobber him.
I think you're looking at it wrong.
Cain landed a sledgehammer early in the fight. After knocking him down, Cain followed up with 5 hard punches before JDS managed to get up. JDS was a zombie for the rest of the fight. Beating him "everywhere" was irrelevant, since he was just beating up a zombie.
JDS had his own moment like that in the first fight, but he KO'd Cain right then and there.
I think Cain is the superior fighter, and if they both weighed 135 lbs, I'd agree with you regarding the likely result.
But they don't, they are HW with massive power.
There are many cases of a strong opponent landing a big punch early in a fight in the 125-155 classes. But the power isn't there to finish the job, so the other guy has a chance to come back and show his superiority and win.
If Cain gets hit in the head, he won't have a chance to come back and win like that. Also, JDS isn't that easy to take down, or keep down. If Cain gets the TD early, but doesn't land a HUGE punch like he did last time, then what?
I'll say anywhere from 60/40 to 65/35 in favor of Cain. If he wins, well, IMO he landed in the majority, that's all. The result doesn't mean that it couldn't have landed in the minority.
This isn't GSP vs Dan Hardy, which is what you're making it out to be.