Save your logic containing essays for another manga. They can be good, but they are just in the wrong place.
"Perospero defeated Chopper and Brook so it's impossible for them to defeat Flying Six"
Reality:
Same Brook then speedblitzed not Perospero but fucking Big Mom, in same arc Perospero offscreened him.
Same Chopper then tanked not Perospero but fucking Big Mom's attack, in same arc Perospero offscreened him.
"Franky has the strength to blabla"
Reality: If anything, poor Franky was reduced from ~ with W7 Luffy (W7 Franky), to now fall below even Sanji.
"Robin will fight Black Maria"
Reality: Robin isn't fighter anymore, the fighter / assassin Robin who low diffed Pell, the Kyros equivalent for Dressrosa, or Ashura equivalent for Wano, was good old alabasta Robin. Now she doesn't fight anymore, she exists as Poneglyph translating machine and background eye candy.