Anyone of them could beat him, without help from the others.
You can't make these type of battle, it against the rules (and are lazy)
The kings play rock paper scissors to determine who has to "fight" Ichigo, the loser one-shots him in 1 second and joins the other kings to have a feast (not on ichigo). By the way, his strongest attack would do jack shit to them, I doubt Zebra would even notice it (sound membrane), Toriko might stagger a little, Coco's poison membrane > Mugetsu, Sani reflects that shit back at him, good day sir.
EDIT: Any of the kings is fully capable of soloing the HST, Toriko has long surpassed the HST, and most recently YYH