Luffy, Loki, and Brook vs GunkImu
Sanji vs Sommers
These are the 2 locked matchups in my mind
Zoro’s is a bit more complicated. Killingham fits the usual formula but then that would leave Dorry and Brogy to be dealt with by… no one
And if Zoro doesn’t fight Killingham then I’m not sure who else could take him out. I wanna say this would be Usopp’s time to shine but it would be hard for Usopp to defeat a (seemingly) skilled fighter like Killingham with nothing but trickery
As for the rest of the Strawhats I think some of them go deal with the fire, others go lead the kids, and I wouldn’t be surprised if a few of them assisted in the fights