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
It’s what Nolan told him about holding back. Viltrumites fought with intent to kill, each blow intended for max damage, Mark was fighting like he was against Maulers, and not for his life.
Even though he’s young he is still pretty strong. This is minor spoiler, but in some parallel universes Mark managed to kill his Father, so not so weak after all