Zoro won’t fight King, if he does it will be a brief clash. Zoro will be part of the Kaido fight with the rest of the Worst Generation. The first guys to reach Kaido will be the 4 who started this raid on the front lines together: Luffy, Kidd, Zoro, and Killer. The rest of the Supernova will join the fight later into the fight.
For now Marco will take King while Drake takes Queen. After Sanji gets freed he will either replace Drake or team up with him against Queen. When Drake is done with that he’ll go to the roof to be part of the Worst gen team up.
As for Jack, he’s getting used as a quick warmup for Luffy or Luffy and Kidd. I don’t see Killer vs Jack happening because first of all it would honestly be a waste of time. Luffy, Kidd, Killer, and Zoro should all get to the roof at the same time so Killer vs Jack would probably take too long. Just let Killer flex in the Kaido fight. And secondly, Luffy promised to kick Jacks ass.