And Jack is still the best example of what I am trying to point out here. Oda had him fight the entire Sulong Mink army, and then fight Sulong Duke and Neko at the same time. That set up his defeat at the hands of Sulong Duke.
Meanwhile, characters like Queen and King have suffered barely any damage.
If the supposed weakest of the Calamities needs to be heavily damaged in order to setup up his defeat, then what sense at all does it make for the two stronger ones, who are barely damaged at all, will lose solo to two opponents who are way more damaged than they are?