What if Luffy had a sister he grew up with.
Luffy had trained in actual Martial Arts.
Certain characters joined the crew, I.e. Gin, Wyper...
If Robin was a physical fighter and used her DF in conjunction with it instead of just clutching.
If Nami had her Axe and robotic arm, that I saw before and how that would play out.
If Nojiko joined and how the dynamic would play out and what fighting style she'd have.