I don’t think King is that far above Marco (King >> Marco) but it’s pretty clear that he’s stronger (King >= Marco).
Even though Marco was exhausted bcuz of the 2v1 and having to protect the live floor (via healing and tanking attacks to guard others), the fact that King essentially forced Marco to take a knee without his hybrid form (as far as we know) is enough to say King would defeat Marco 1v1.
This isn’t to discredit Marco though, he’s still 10x more useful than King in a fight against top tiers.