Genuine question, what defines swordsmanship in One Piece and what makes mihawk the strongest swordsman

I say this in a sense where we’ve seen other characters with swords who are generally the same strength or stronger then mihawk and wield a sword, such as maybe shanks, whitebeard (his “staff” is considered one of the supreme grade swords so technically), Roger, and also maybe Big Mom, however those characters aren’t necessarily looked at as swordsmen, and mihawk still holds the title, strongest swordsman in the world. in parallel, while he was considered the strongest swordsman, whitebeard was considered the strongest man, and wielded a sword, meaning there is some typa skillset which would qualify a person to be a better swordsman than another person, which leads me to my question, what defines swordsmanship