People don't seem to understand what King and Zoro were saying when they talk about swordsmanship so I'm going to explain it.
1 - Being a swordsman doesn't mean you're limited to just swordsmanship. In other words, there's no such thing as pure swordsman. A lot of us have tried to explain that several times. A swordsman can punch, kick, used hak, another weapon or anything else they want to use.
2 - In a real fight anything goes. There's no such thing as a fair fight. We saw that when Zoro used Killer's own scythe.