people can still fight after dropping their swords, then mihawk's title would mean nothing for them. A swordsman can still be a fighter at the same time, which means mihawk's title is a very small and he can still lose against inferior swordsman, if that inferior swordsman is a better fighter than mihawk, which is why it's not weird to see Vista being equal to mihawk, because a fight is not all about being a swordsman, there are more to it, a lot more.