Other than Caribou and possibly Tama, I’m not sure that any of these people would move the needle at all against two Yonko.
First of all, how would they get to Onigashima? We’re seeing that the waters between mainland Wano and Kaido’s stomping ground are treacherous in general, and even more so if you don’t have the power that the alliance possesses.
Second, these people seemingly have other things to worry about outside of bringing down Orochi and his enforcer(s) - Toko is mourning her dead father, Tsuru has to defend her tea shop, Tenguyama has to protect Tama AND the precious blades under his watch. Even if they were strong enough to hang around, they’re all distracted with other issues at the moment.
Third, as I’ve kinda alluded to throughout, none of these people have shown any abilities that would prove useful in the impending clash. We know plenty of strong folks are gonna somehow show up to help our protagonists, but there’s been zero indication that any of the common Wano folk are gonna be a part of the cavalry. Just don’t see any use in them coming to raid when we all know they’d be killed before reaching the inner sanctum on the island.
These characters have parts to play story wise, and I’m sure they’ll have some support to provide at some point, but to me, they’re complete non-factors when it comes to battling Kaido and Big Mom. Again, Caribou (a crafty, conniving Logia user) and Tama (taming the SMILE users) can definitely contribute in a tangible way, but the rest cannot feasibly alter the outcome here.