Deidaras Explosive Style was weak to and nullified by Sasukes Lighting style. Why? Even though Explosive Style is Earth + Fire, Earth is weak to Lightning and therefore it was nullified. All Sasuke needed was an Element strong against Earth, but not weak to fire. This goes to show that even though a kekegenkai, they still hold the properties of their original natures.
Since Wood Style is Water + Earth, an element strong versus Earth but not weak to Water (Lightning) would cancel it out, like in Deidaras situation. We have 3 of the best Lightning users in the series who can all fight close to Hashiramas level. I say all of them because Young Ay fought on par with Hachibi, knocking it to the ground and severing its horn all with just the force of his karate chop. Kakashi is well..... Kakashi. Darui beat GinKin bros, who defeated Tobirama + Nidaime Raikage so that holds lots of weight considering Tobi and Hashi were really close in skill.
So yeah, none of them are on Hashiramas level, but they aren't completely outclassed and beaten like stupid fodders. I can see Hashirama winning with his gargantuan Wood techniques but then again we have Ay who can literally just run through that shit in V2 like the Juggernaut, Kakashi can who create long Lighting Blade Chains to run and sever it all, and Darui with his Black Lightning and Jubi ranged Laser Circus (its made of lightning too). Kamui is not the reason they stand a chance here, its because they all top tier Lighting users, which is why I think the OP made it that way. If they nullify Wood Style ( which i suspect happens) they can win. If not, Hashirama solos them high difficulty.