We already have:
Marco vs King
Sanji vs Queen
Inurashi vs Jack
And this represents Three Alliances of Straw Hats + Scabbards + Marco vs Three Calamities
And then we have:
Jinbe vs Who's Who
Franky vs Sasaki
Brook & Robin vs Black Maria
Nami & Usopp vs Ulti & Page One (Already Ended)
And this represents Straw Hats vs Tobbi Roppo
And then we have:
Drake vs Apoo
Killer vs Hawkins
And this represents Supernova Fights
And finally we have:
Law + Kid vs Big Mom
Luffy + Zoro vs Kaido
This represents the Main Fight of Main Duo vs Kaido & Additional Supernova vs Additional Yonko
And then we have some additional "Grudge" Fights which are:
Minks (Carrot & then Neko) vs Perospero
Raizo vs Fukuro
Kin'emon & Kiku vs Kanjuro (Already Ended)
So it all makes sense, we have:
Calamities vs Straw Hat Samurai Marco Alliance (Animal Fight / Science Fight / Bird Fight)
Flying Six vs Straw Hats
Supernova vs Supernova
Main Duo & Top Supernova Duo vs Yonko
Additional Scabbards Revenge Fights
Also remember that Wano was Planned before OP Started & at the time Oda never thought about Supernova, they were only added Decade later, so at first there were no Law & Kid Alliance, there were no Hawkins, Apoo & Drake among Beasts Pirates
This is why Oda added Big Mom to Wano so that she takes on the Additional Characters he made (Kid & Law)
And then made Other Supernova Fight each other (Drake & Killer vs Hawkins & Apoo), this way he perfectly preserves his Original Wano Scenario
So when we remove BM & Supernova from the Equation, what is Oda's Original Roof Battle????
It's obviously Luffy + Zoro vs Kaido (And possibly Yamato & Momo join too)