What the anime proved
1. King is vastly superior to Kakuri in terms of AP, Durability, Speed, DC, AOE, Manuverability, and Defense.
2. Kings last attack was Yonko caliber. The same cannot be said for either sanji or katakuri or marco.
3. King just like sanji turned completely invisible when using his super speed yet zoro countered effortlessly. So there is 0 proof that sanji is above king in speed especially when sanji fought a person vastly slower than himself and zoros opponent.
4. King even in flame mode was scared of zoro attacking him and defended himself with a sword even though he had his flame on.
5. King had his flame on while using his final grand attack in which zoro still actually cut him
6. Zoro seems to have better portrayal of observation haki in comparison to sanji since he was able to track the movements of someone as fast or even faster than germa bossted sanji
7. This also proves that zoro indeed used coc to pushed king off him trying to take his blades
8. Anime also proves that zoros stamina was fine. It was simply enma still handicapping zoro trying to take to much of his haki while he was ending king.
9. Anime also proves that King's fire did indeed become MAGMA in form and heat.