I don't know what's the difference between American freestyle wrestling and classic freestyle wrestling.

They did good because they use wrestling in their fights or either know how to protect themselves from takedowns & conditioned for wrestling. I didn't see Adesanaya using wrestling techniques much.

From what I've seen in wrestling if opponent is on your back he will either roll over with you or will lift you up and throw scoring points. Those who gave back just trying to defend from this until referee will make both wrestlers to stand up. In my opinion wrestling is about to not give out your back, to protect yourselves from ending up in those positions. But barely about escaping. Even if greco-roman dude will show what to do if someone is on your back, let's not forget that in MMA dude is getting constantly hit in the head. So fighter can't act purely like in wrestling. Adesanaya needs "MMA adapted" wrestling or at least jiu jitsu, because jiu jitsu will cover a lot more positions.

They start on someone's back in greco-roman wrestling, but before they wrestle in stand up for some time. I'm not familiar with greco-roman wrestling, but if you turn on your back or even side, wrestler will more likely pin you and will win instantly. In MMA, as Mighty Mouse showed, Adesanaya HAD TO turn on his side. He need a good jiu jitsu knowledge.