I believe you but can you link me the page number/ chapter so I can get context?
Jacks blade was very focal to his fights so far, and was a special type of blade. Queen we haven't seen fight, but I doubt he carrys a sword that ugly because it looks cool, he probably does use his sword to fight in base.
Kaku didn't pride himself on his Geppou, yes he used it, but he was focused on his unique rankyaku, just like Jyabara was focused on his unique tekkai. If King doesn't utilise his fruit in an open air battle then that is a lot more of a PIS downgrade than someone who uses four sword style not using geppou excessively indoors when it would limit his swords. Do you literally just want King to fly at low altitudes at Zoro to clash with him and give him opportunity to hit him?
Oden cheap shotted a low floating on clouds transformed slow kaido, transformed king is not slow and is not a massive target like Kaido as I have previously outlined, it is apples and oranges, as another example if someone like Doflamingo wanted to camp in the sky/ run away there is nothing Zoro could do to stop him (without the aid of someone to throw him like vs. Pica), mobility matters outside of PIS.
Barrier haki is the pinnacle of breath of all things, that is pure swordsmanship in my book, using abilities that not everyone has ability to learn i.e. fruits/ advanced CoC takes you away from being a pure swordsman, as does using martial arts kicks as your primary combat style.