We know there are ways to definitively defeat and stop the god knights outside of just conquerors. Imo it will be up to the trio that didn’t get any fights in Wano to figure out how to defeat them. That doesn’t necessarily mean they’ll be fighting them alone just the ones to figure out a plan to stop them
With how hectic it is in the holy land Imu is definitely going to need to leave before the mission is complete. Brook is tied to gunko and through his music he’ll most likely revert her mind back to normal. At least long enough for them to incapacitate her
Usopp stopping Killingham the guy that makes nightmares come to life makes too much sense not to happen. We’ve seen Usopp defeat people multiple times without actually hurting them with the 2 big examples being Perona and Sugar. Him ironically using fear to knock them out which would be a pretty funny way to take Killingham out as well. Even if it doesn’t stop his dream monsters maybe it at least stops him from creating more by maybe closing the portal too
That leaves chopper figuring out a way to stop sommers. While I do think Sanji might be damage Sommers when unlocking conquerors I don’t necessarily think he will be the one to defeat him since he’ll still be able to regenerate back. How exactly will chopper stop him? Idk tbh but I would like to see him use brain point scope thing because I think it’s cool. He could figure out how to crush him so he can’t move, throw him in the ocean, etc
As for the monster trio probably the Domi Reversi giants. Loki likely being turned before Imu leaves and oda probably just having dorry and brogy fight each other long enough for Zoro and Sanji to reunite again after figuring out how to consciously use conquerors haki