Hm... I thought Perospero is a 1st commander. This family is messy. Well, Katakuri deserve to be given that much. He is quite promising. A chance for Luffy to level up.
He's the first son of Linlin and even Luffy's Red hawk one shot his candy maiden. Think of it in this perspective. During the Alabasta arc there are the obvious strong subordinates such as Daz and Bon clay, then there is the hax devil fruit with really strong powers that come in 3rd place in the latter which is Galdino.
Perospero is somewhat the Galdino of the group (3rd-4th) strongest in the Big mam pirates with a very powerful devil fruit with no crazy physical strength to match someone like Luffy, Jinbei, or even Sanji. Still strong enough to beat Pedro but nothing crazy.
Beside that you're right.
Apparently Cracker is weak physically. Not that much weak. Just perhaps as strong as -- a~ Blueno? I dunno. It took him one shot and the guy passed out. Only his biscuits what kept the whole fight to last like 10 hours. This fight didn't change Luffy that much. Not like how Luffy been through against Lucci and Doffy. And lucky we have Katakuri who is of the same calibur as Lucci and Doffy. The real fight and suffering is this coming fight between Luffy and Katakuri, and if Oda screwed it up, I'll curse Oda till death. This is not Fairy Fail, and I won't accept any miss of a chance like this.
Yeah I know Cracker is weak, that's why I said his biscuits are strong. He said his biscuits are physically strong enough to charge into Gear 3. When it comes to the man bodies of the Big mam crew (besides Big mam) they are all not as physically strong as Lucci or even Doflamingo. They're just powerful devil fruit users with expert haki in one field over the other.
Luffy so far in the show has been shown to be physically stronger than his opponents (besides yonkous) but has shitty experience then almost every big name he's encounter. Doflamingo fight for an example...
Gear 2 was faster than Dofy but his techniques were too weak to harm him
Gear 3 was too strong for Dofy to fight head on so Dofy used his speed to by pass it and pummel his face in.
Gear 4 was overall too fast, stronger, and durable than Dofy but his stamina was shit and couldn't last longer than 5 punches to Dofy before deflating.
Regardless of the situation that they were in before the one on one fight, Luffy needs to work on perfecting his Gears and stamina. I think awakening is the way to go.