That's the thing though, Overeem has so many more ways to win the fight. Trust me, he's not getting flash KO'd like Cain. People talk crap about his chin, but he's never been flash KO'd, even by powerful strikers who knock people out with one punch (Lidell, Shogun, Hari), he was finished by volume strikes. If Overeem starts losing his stand up, I guaran-damn-tee it, he will clinch up and ragdoll JDS, possibly pounding him out or submitting him.
Overeem is not the same guy from his 205 days. He didn't only improve his physique and technical abilities, his fight IQ has gone way up. He's a very intelligent fighter. Before this fight people were doubting his ability striking with wrestlers and smaller gloves, that his style of striking in K-1 where he covers up with the big gloves wouldn't work, etc. that he has zero head movement.. What did he do in his fight? He kept his hands low, wide stance to be ready for the shot, avoided all of Brock's strikes (except for the grazing jab) with head movement.
He was wary of Werdum on the ground, even though he had top position multiple times. He won't be scared to go to the ground with JDS. He's just going to be too much for him.