He’s what? 18? Basically nothing in viltrumite timeframe.
Literally gets dominated by Lucan using one finger.
Then he gets his ass beat by Thula, who has hundreds of years of experience minimum, mind you viltrumites get stronger with age, aaand somehow a pep talk allows him to almost kill her? What? Mind you, in the comics this Thula threw down with Battle Beast and walked away alive
I actually think the opposite. Mark didnt beat the shit out of them, if Nolan wasnt OP, they both would die.
And the reason why Mark was able to keep up with the fight later was simple, Nolan says it outloud. Mark isnt a viltrumite, he doesnt fight to kill. He fights expecting the other side give up. So when Nolan gave him some Goku speech, he just fought for his life instead of trying to protect his enemies too.
And also there is one other reason too but that would be a spoiler.