IM has the 5 Gorosei and 4 Admirals as his main henchmen.
SH are 9 Crew Members + Luffy. SH’s May add someone to their crew to make 10 members, but IM may add Aokiji or Kong to his roster of fighters.
So for me the final matches will be
SH Crew Combined vs IM
Luffy vs Akainu
Zoro vs Fujitora
Sanji vs Kizaru
Jinbei vs GreenBull
Robin vs Aokiji
Brook vs Saturn
Nami vs Venus
Franky, Chopper, Ussop vs the other Gorosei