Kaku was much stronger because he uses swords + DF
It’s stated those numbers only factor in physical strength and don’t factor in Devil fruits. Kaku’s swordsmanship skill may put him over Jabra but Jabra was much more experienced with his fruit.
None of this was an accident. Oda likes for Zoro & Sanji fans to argue and he purposefully made it as murky as possible with Kaku & Jabra. That’s why I think King will be slightly stronger than Queen, but Queen has his technology & Zoro will be nerfed for the fight. It’ll start brand new arguments. Oda is trolling us lol.
Luffy > Zoro > Sanji with Zoro closer to Luffy’s end of the scale. But Oda muddies the water on purpose just to stir up the hornets nest.
Zoro fans can rightly say he beat King at less than 100% and Sanji fans can say they fought similar strength opponents. Oda makes it clear that Zoro is significantly stronger but every now and then he likes to give people something to fight about to keep it going.