I still think Overeem will beat JDS if they clash, and I am very confident he will be knocking Bigfoot out. Cain on the other hand is going to be a huge test. I say this because I think the weakest part of his game is his cardio, especially compared to the beast cardio we have seen Cain display. Overeem could easily drop Cain with just one well landed strike, and his tdd is very good.
Surely JDS' endurance is just as good? Seeing as he fought 25 minutes with Cain and did not get finished, but took way more damage.
Overeem is a huge threat no doubt, but JDS and Cain share the measuring stick right now and should both be favorite over him.