Flying 6 vs SHs is basically confirmed with separate locations for them.
Kaido vs Luffy
Big Mom vs Kid and team up maybe with Marco
King vs Zoro
Queen vs Law
Jack vs Jimbei
Who's Who vs Sanji
Sasaki vs Franky
Ulti vs Nami
Maria vs Robin
Page One vs Chopper and Usopp
Drake and Hawkins are the wild cards
9 numbers vs 9 scabbards
Maybe its my headcanon but it makes sense
Apoo is entry fight for Kid, maybe Killer will take over later.
Luffy will save himself for Kaido, won't have a Blueno scene here.
Another obvious one is Minks vs Smile users. Oda gave them incredible designs so it'll be a feast to watch
Not sure about Law, Sanji and Kid exact matchups.
Marco will first fight against King and then when Zoro comes he will go give back up against Big Mom. He might back up multiple fighters with his abilities I'm thinking . Big Mom pirates will come very late. I'm thinking SWORD will intervene with them or at least Drake and Hawkins might.
*totally forgot about Brook. Maybe another covert mission to steal ponyglyph? Or a tag team with Franky maybe.