sasuke>deidara>gaara doesnt really work
gaara and deidara are both capable of fighting at VERY long distances, literally hundreds of feet away, sasuke does have long range attacks however he is much more of a close-mid range fighter, who gaara could beat in theory.
Its not about who beat who, some peoples skills allow them to beat others when another can beat the vice versa.
For example orochimaru got away from 4tails naruto without a scratch and thats when he was weak and his body was rejecting him, jiraiya nearly died, however orochimaru and jiraiya have been rivals and it has been shown they have fought and both survived.
Transitive inference wise A>B>C 4tails is orochimaru>4tails>jiraiya
However orochimaru and jiraiya are at least equal to have both fought and survive.
Jiraiya is also most likely stronger given his fight against pain because even though orochimaru could do pretty good, i cant see him doing pain over quite like jiraiya did.
sasuke is an emo *** who is powerful, but deidara and itachi are dead because of him, and quite frankly i think having deidara and itachi in akatsuki makes it a LOT stronger than sasuke and his gays.
Im not saying sasukes weak, im just saying he is nowhere near akatsuki level.
i do believe kakashi stated opening 8 gates gives you temporarily more power than any hokage, and kisame was defeated with 30% chakra like you say, so hes potentially 3.3x more powerful than any hokage.
Kisame only needed to stall them, there would be little point wasting time clinging onto life from gais team to stall them more, he stalled them enough already, as was shown given they succeeded in extracting gaaras shukaku.
Zetsu may only be a spy, but to be in akatsuki you need to be strong.
Pain stated to konan "dont wait for me, if you can take him yourself do so"
He wouldnt say that knowing she had no chance, im sure konan simply had too many feelings still and pain had to take it from there.
I just hate sasuke, i dont mind reading his parts in the manga, theyre usually good and entertaining, but he is too emo for my liking lol