In regard to the Coola statement, Coola stated later on that SSJ must've been what Goku used to beat Freeza, suggesting that even if we were to take his first statement at face value, he was likely assuming Freeza didn't get a chance to use his full power. No real need to hax M5 characters.
I'd personally place Coola a little above Gohan, so he'd take this. Supernova would definitely seal the deal, considering how much strain it was putting on someone who was stomping Coola prior to it.