Coco gets that a lot. But his fans usually admit he's the weakest. Toriko fans are some of the most reasonable. I am one. Lol. But my favorite King changes a lot. It's one of the few main casts where I like all of them. But anyway, no doubt that Coco is the smartest and most resourceful. From a total power standpoint it's probably Zebra > Sunny > Toriko > Coco. In brains it's the opposite, Coco > Toriko > Sunny > Zebra. But overall combat prowess Toriko is probably the King. He's not the best in anything (except maybe brute strength) but he has no weakness relative to the others who each lack something.
okay, so maybe Coco is the weakest in overall power. but he's pretty much the Batman of the Kings. he's by far the best tactician, and if he can survive long enough, he could probably find a way to trick Sani into a trap. he's extremely resourceful as a fighter, and could probably defeat any of the others in a fight through battle prowess and tactics, despite being the weakest physically. well, thats my opinion at least. Coco is my favorite of the kings, so maybe its just my fanboyism speaking lol
ironically, i think Coco has some of the most fans out of the Kings. he is the weakest power wise, and most accept this. but if you give him some time, he'll outsmart and outmanuver you easily. i personally like him for that reason, even though he's the weakest he has the tactical ability and brains to win against a more powerful opponent.
Toriko is my second favorite for the sole fact that he's just such a badass. and like you pointed out, he's the most balanced of the kings, and pretty much the unofficial leader as well.
also agree with this!