Your top tier could never.
Mihawk just casully flexing creates one of the best feats in the series. Truly the WSS ๐๐๐
I may be reachjng here but I believe he was merely trying to showLuffy the massive gap in their capabilities with that slash. He intended to only cut the ice berg and nothing else.
Remember what he said to Zoro in his introduction -that swordsmanship should have grace and that he's "not a stupid beast that would hunt rabbits with his full power"
He's not at full power ofc.
But a slash that powerful isn't exactly weak, nor is it graceful for a off glance blow to tear up a frozen tsunami. He's allowing the blow to happen, so that Luffy can understand what/who are at the top; and just what kind of people he's trying to oppose by partaking in the war against the WG.
What a great man.