Smoker for sure.
He was the true marine rival to Luffy, but Loda dropped him mid way for Coby SMH. I don't mind Coby becoming strong, but EoS Smoker should 100% be an admiral.
Doflamingo.
With him IDK what is Oda's intention, like whether him going down early like Crocodile. But feats make it arguable he is Cracker level.
He was built like an evil version of Luffy. A character who shared bonds with his crewmates, whose crewmates would readily sacrifice for him without even a mention, who was running for the PK and king of the world in his own way. The conqueror's spirit he showed was akin to Yonkos, he shouldn't even be mentioned in the same line as low-end commanders like Cracker given his narrative.
Such a character should be no less than an admiral. I would give him a prison boost and get him to be at least comparable to the new admirals (GB/Fuji).
Kid.
People don't see it now, but back before raid was a thing, Kid being a true rival to Luffy was not a hot take. But now he's a joke, even though he is a conqueror and has a legit first mate built alike Zoro in Killer.
Brook
Amongst my fav Strawhats, but he is very neglected by Oda. Why didn't he even get a Tobiroppo fight in Wano?