Just ask this yourself
Will you prefer having Zoro vs Daz Bones, or Zoro helping Luffy fought Crocodile?
Will you prefer having Zoro vs Kaku, or Zoro helping Luffy against Lucci?
Will you prefer having Zoro vs Pica, or Zoro helping Luffy against Doffy?
I myself prefer those Daz Bones, Kaku, Pica fights.
Among the polls I chose:
King is Kaido's strongest man
King is formiddable swordsman
Zoro should get proper 1 vs 1 against a swordsman, in Wano arc (the country of swordsman)
But since the poll is limited to 2, then I deleted the second reason.
Let's be honest, before Wano arc officially started and we didn't know yet that 1. King uses a sword 2. Orochi is a scrub, majority of people here prefer Zoro to fight Shogun of Wano instead of King or any other member of Beast Pirates. Zoro vs Powerful Swordsman in Country of Swordsman is more epic than Zoro vs someone not a swordsman. And since now we know Orochi and all of his samurais are scrubs, then King fits this criteria the most.
Battle against Kaido atm is like free for all fight. Scabbards landed hit on him, Luffy landed hit on him, Zoro landed hit on him, Kidd landed hit on him, Killer landed hit on him, Killer landed hit on him.
I would rather Zoro having 1 vs 1 with Hybrid King than joining the battle against Kaido.
Another reason is, battle against antagonist almost always ended up dragging for so long and became uninteresting (Doffy, Hody, Lucci, Croco fights etc). While Zoro's usual fight against the second strongest (and every other SHPs against their enemies) usually ended up without dragging so it still remains interesting.
Those morons who shit on King "mErE cOmMaNdEr", "KiNg iS tRaSh", blabla should shut up. Hybrid King still remains above Dragon Kaido the punching bag.
P.s.
Don't really believe in ZKK. The main reason is I think Yamato will join the crew after Wano, and no matter how bad the relationship between them, it will still be awkward to have your crewmate killled (and behead) your dad.