You guys realize that the dialogue between Zoro and King just serves to prove anyone with a sword is a swordsman in Zoro's eyes?
King says he isn't bound by one fighting style.
Zoro agrees with him. And says he would do other things as well, if necessary.
So the dialogue can only allude to one outcome.
Zoro and King are swordsmen, or they are not. Because they both aren't bound to only using a sword.