King is likely to be on that level. Even though Marco was drained, King still managed to knock him down in base form. It's safe to assume that a FP King is at least comparable to a FP Marco.
Jozu is arguably the strongest character power-wise after Kaido and Big Mom. I wouldn't think Aokiji would be able to lift that giant iceberg with his bare hands. I think we can maybe compare him to Queen. He was able to generate enough power to get Big Mom's memory's back. I'd argue in a fight between Jozu and Queen, the latter would win out in terms of pure endurance and because of his ranged attacks. Unless it's revealed Jozu has advanced armament.
King is like Marco
Queen is like Jozu.
Would they be able to fight an admiral? Sure. I don't think there was any way WB's commanders would have beaten the admirals in any scenario. The point of those fights were to showcase how capable a Yonko crew. They could stall them for a bit, but there is little chance they would win.
Smoothie is hard to gauge since we've seen nothing of her.