Elbaf.
We at least saw what the island was like ib Big Mom's flashback. But can we just see more of the island and its strongest warriors to put an end to the "Giants are just overgrown fodder" mess?
Dorry and Broggy were both exhausted from fighting for many years and one ate an explosive meal, that was why Broggy defeated the former and the latter was sneak trapped by Mr 3. That was not even close too their full potential and you know it.
If anyone wants to bring up Hajrudin losing to Luffy, no shit he is a rookie compared to veterans like Dorry and Broggy. None of the Strawhat Grand Fleet members are close to comparable to the Monster Trio, even the likes of Cavendish and Bartolomeo (who Luffy can also wipe the floor with easily). If he should be downplayed for losing to Luffy, then do the same for Sai and Ideo. He is young and have not tapped into his full potential when he wants to build a giant crew as good as Dorry and Broggy's. He still overpowered Machvise, one of Doffy's lackeys, after taking 10,000 tons of force dropping on his fist.
As for Oimu and Kashii, lets face it, they only guarded against low tier human pirates all their life after being bribed by the Government. They were rusty and overconfident, that was why they gotten overwhelmed by the combined efforts of Galley-La and The Franky Family (Mostly Paulie, Sodom, and Gommorah) which they almost had the upper hand against. On top of already being exhausted from said fight, they faired pretty well against all the Watchdog units and Marines until over an hour of being bombarded by cannon fire and mortars.
John Giant and the Giant Squad were all Vice Admirals, as in they are comparable to the likes of Smoker and Momonga. They were very strong, but unfortunate victims to Whitebeard who is obviously leagues above them. The same Whitebeard who knocked out Sakazuki after the latter taken off half of his face (or gave a second hole in the anime). It would not be fair to downplay them based on that.
Oars was a tough bastard with Luffy's Shadow and Moriah's assistance. All of the Strawhats were bodied except Luffy, who needed shadows of his own to stand a chance against the behemoth. He may have been much stronger in his prime years ago before his death. His descendant Oars Jr was also strong, he was just overwhelmed by three obviously powerful Shichibukai and focused on saving Ace. He still managed to destroy the entire Marineford barricade with the last of his energy after Whitebeard demanded it.
The Yeti Cool Brothers were far from fodder. They managed to defeat three of the Strawhats while they were off guard. Law was just a bad match up for them and Monster Point Chopper (with Franky in his body) only smacked one of the brothers with a large rock while rampaging.
Unfortunately there is not much to say about Morley. Him and all the Revolutionaries were overwhelmed by the Fujitora and Ryokugyu in Mariejois, and going against two admirals at the same time isn't an easy task without a plan.