This is the part I don't agree with. I don't think Jack was superior nor slightly superior to full powered Inu back in Zou. The fact that Wanda basically implied that the fights were stalemate supports this.
Also, even though Inu lost a leg, that got compensated with haki bloom in Onigashima.
Also Jack wasn't in hybrid when he was backed by gifters. IIRC he went hybrid after Tama turned those gifters against each other.
Fair enough, but I think the fact that he fought continuously for five days without getting overpowered while the dukes got to replenish their energy after every 12 hours does imply slight superiority. It makes sense for him to be equally unsuccessful in overpowering the Dukes as he was fighting restlessly while the gap isn't that big.
I don't think Inu got a Haki boost in Onigashima; was it implied? Yes, Jack used hybrid after the gifters are taken out. That should've given him a decisive edge given how Jack is just as powerful in the base, but it didn't, making me think he's far too injured for even his hybrid form to make a difference.
This part is fair but I think factoring in Jack's reinforcements whiles Peros had non closes the gap for me. Also Wanda and Carrot even in Sulong never landed a hit on Peros. He had no new wounds.
Agreed, the reinforcements make things easier for Jack which cements my argument above even further. Pero Vs Wanda and Carrot lasted for a decent amount of time IMO. It started when BM left and before Kaido defeated the scabbards, and it ended after Luffy ran out of G4. I think he took some beating from them given he talks about how they'd have potentially won if it weren't for the weather change.
Jack, on the other hand, knocked out two people stronger than Wano and a few other Sulong Minks with one swing of his trunk. There is a considerable gap b/w the two if you ask me.