Jack was underwhelming because we didn't see much of him, but canonicaly he's as strong as cracker which puts him on the same tier as doffy
Was doffy a better antagonist? Yeah he was, queen wasn't much of a character, he was an obstacle that sanji was meant to overcome psychologically and physically
Was he a better fighter? No
Doffy did not neg diff sanji back in dresrosa lmao
He only won because sanji didn't know his powers
By your logic apoo neg diffed luffy
Sanji didn't even use hell memories, and he landed only one no named attack
Doffy had to dodge the other basic kick sanji threw at him, and then blocked poêle à frire spectre which is arguably one of sanji's weakest attacks, he only uses it for fodder control
Queen's gimmicks put him above doffy
Jack's endurance and raw strength puts him on the same level