The problem is there is no 6 man group in SHP. So either:
1. Saturn goes down and the EB5 take down Imu and the gorosei
Or
2. The gorosei don’t fight the straw hats
I like option 2 personally lmao
I think we are looking at this too reductively. It doesnt just have to be the crew.
The ones that fight the Gorosei can easily be Zoro, Sanji, Sabo, Kid and Law, whom are basically Luffy's strongest and closest allies.
Then you can have the rest (i.e. 7 Strawhats + Supernova allies (Killer, Urouge, Bonney, Drake, Hawkins, Apoo, and Bege) + Revo commanders fight God Knights, CP0, Kong, etc.
Its going to be a big mess lol, especially now we know that they fight. I dont even think the Marines will be involved at this part, they'll lose earlier