Marco specifically said he was holding off 2 guys with above 1 billion bounty in chapter 1006, he obviously didn't mean its only for a second its since chapter 1000 where King and Queen failed to stop Marco from sending Zoro to the rooftop. Which is why King saying he is busy enough to not even go to finish 9 scabbards is important in Ch.1004 then we see Marco vs King and some flying gifter in Ch. 1005 then in Ch.1006 before Queen could attack Hyogoro Marco stops Queen then King tries to cheap shot Marco while Queen was also attacking Marco with a laser but King ends up on his butt with a bluebird attack then a flying knee makes King bleed from his mouth, before Queen can cheap-shot Marco in return Marco sends Queen flying too. In chapter 1007 Marco holds Queen's neck and lets Chopper slap him.
It wouldn't make sense for King to fooling around and take damages from Marco when he needed to go and finish 9 scabbards, he was focusing on Marco, so your ''what we see counts'' only logic doesn't work due to Marco's statement on holding off both Queen and King in chapter 1006 and King saying he is busy in chapter 1004. The only reason King couldn't go anywhere else was Marco.