If you want a possible pattern to look at, its very possible that Oda is only having strawhats fight beast pirates.
Let's just assume Big Mom goes to Kid/Killer really, while Luffy/Zoro take on Kaido, a parallel that people seem to be agreeing with at this time. Let's say also at some point, Zoro ends up fighting King by the end of the arc. Some people disagree with that, but that's alright.
Brook and Robin are heading into the mansion. Queen conspicuously is interest in Sanji, thus potentially having Brook/Robin take over Sanjis fight with Black Maria
Then you have Nami and Usopp, who only fought Ulti. Chopper is the last remaining current strawhat in the area. At this time, Carrot is fighting a BMP, but Yamato is free and has yet to show off her powers. She's not up at the top with the Yonko, and Jack is literally the only other Beast Pirate missing from the action right now.
Thus you'd get this very interesting, clean matchup between Luffy's crew and Kaido's:
- Luffy vs Kaido
- Zoro vs King (yes, after fighting Kaido for a while)
- Sanji vs Queen
- Yamato vs Jack
- Jinbe vs WsW
- Franky vs Sasaki
- Brook/Robin vs Black Maria
- Chopper vs P1
- Usopp/Nami vs Ulti
Funny enough, the above is how people have been powerscaling the SHP (sans Yamato, but have been placing her near Sanji/Jinbe anyway), and how the Beasts Pirates also seem to be grouped in terms of strength (though Ulti/P1 are probably interchangeable).
To me this just looks extremely clean, and while we probably need another 10-20 chapters to really determine who everyone is going to fight, its been my bet for the past month now.
No knock on Carrot, but it does seem to me like Oda will either not deal with Big Mom this arc, or he will have the other Supernova like Kid, Killer, Law, Drake, Apoo and Hawkins potentially handle Big Mom and her top crew members.