First rule of powerscaling is to elevate someone who shows good feats against established strong characters.
Doflamingo placement in power scaling has been established by fighting Crocodile who later clashed with Mihawk. Oda already established Doflamingo as a strong combatant who could hold his own against top tiers via Crocodile. So we should elevate anyone who shows amazing feats against Doflamingo like Boundman.
I already made a thread why Boundman was more impressive than Marco against Big Mom you can check.
Jack on the other hand is weaker than Queen who got 2 shot by non haki Big Mom. That's embarrassing. Those sulong minks losing to Jack only make them look even more pathetic.