It is an argument when Zoro, after achieving Conquerors Haki and Advanced Conquerors Haki and being able to infused his swords with said CoC Haki, basically says, "This is still not enough, I have to become stronger still" unless you think Mihawk can be stronger than the current Zoro without possessing Conquerors Haki or being able to infuse Yoru with it.
And in case you are, go off King. Not brave enough to wank Mihawk as that strong without even having the cheat code literally every other vaguely strong fighter seems to be using at this point, but you go ahead and put Mihawk on that pedestal. That is certainly some Top 1 enegry.