Tbh, the rooftop five should have fought against Kaido and Big Mom till the end all together.
Cause not only the spectacle would be better cause of more uniqiue charachter abilitys, combinations and interactions but it would fit more the theme of "Luffys true strength is to make allies", which would make it more unique than "yeah hes the main guy so he automaticly gets strong enough to defeat the strongest bad guy".
But actually I would liked the cope theory more which said the nine shadows are the strawhat pirates and make the battle a team up of the whole crew against Kaido, with everyone synergising with their abilities and personalities, and you can even still have Luffy as the last one standing left to give the finishing blow to combine both "my crew does what I cant but I am the one that saves them" things into one cohesive thing.
But nah Luffy just punches Kaido, gg no re😂