I’m not sure about the speed situation
@Sentinel. Never been good at measuring but using the ability to avoid lightning as a basic metric I don’t think the verses are too comparable. CP-9 is able to dodge Nami’s Attacks, whereas a high tier like Itachi can react but can’t physically move in time to stop Kirin. If Nagato can’t react to Doffy, he’s be bisected.
For the general match up, assuming I’m wrong. I think the really devastating factor is that a character like Nagato can produce several counters to Jinbe and Doffy on his own. Chibaku Tensei, Chou shinra Tensei, bansho tenin can be fatal if caught off guard. Ashura’s form morphing ability and multiple vision can defend against parasite. Hell, Nagato might be able to cripple Doffy’s ability to fly considering he has ninjutsu that alters the precipitation in the air, opening the door to clear the area of clouds.
Add in Kisame, who can unleash lakes with ease, and I think nagato stands a really good chance of draggijg doflaminngo into the water and stealing his soul. Jinbe becomes a little trickier in water but I think kisame’s manipulation of suiton can withstand Jinbe’s until Doffy is done.