Hidan Kakuzu= Loses. End of.
Deidara Sasori= Loses. End of.
Sasori Oro= Would be a good match, but Hashirama is still too good.
Itachi Kisame= Best chance of winning, as Itachi is VERY intelligent, and Kisame can absorb ninjutsu. Samehada is also a fearsome weapon. Id say these guys can pull it off. Throughout this manga, we've seen intelligence trump power (just look at my avatar!). Itachi is definitely one of the most intelligent characters we've met. Not saying Hashirama is an idiot, but Itachi's intelligence isnt matched by many. Id say he can figure out wood release's weakness, and counter it, with the help of Kisame, ofc. As Itachi himself said, "Every jutsu has a weakness" (said this while finding the weakness of Chibaku Tensei, a jutsu used by the SO6P himself, albeit on a bigger scale). If Itachi can figure out Chibaku Tensei, he can figure out Mokuton.
Nagato Konan= Basically its Nagato vs Hashirama. Without prior knowedge, this would be a very interesting match, but based on feats, hype, and general facts given to us in the manga, Hashirama still edges it, although barely. Dont anyone spit bull**** about Konan's 600Billion tags, as that took her days, maybe weeks to make. Dont think she has that much time against the most powerful character in Naruto (outside of SO6P obviously)
If you were to mix n match the people, the only pair that I can safely bet on to win against Hashirama is Itachi Nagato. Thats just a ridiculously powerful pairing, probably the best Akatsuki pair in terms of fight win probability.
