Well maybe not chopper but when chopper turns into his monster point he is incredibly strong. Anyways here’s why Nami is stronger than usopp.
Weapons: Usopp has his slingshot but can’t do anything in close range. Nami can make storm clouds and fight people with the clima takt.
Bravery: Usopp is a total woos and Nami has the audacity to stand up to sanji, zoro, and luffy. Usopp would never do that.
Haki: Usopp wins just because he has observation and Nami doesn’t have any.
1v1 combat: Nami has Zeus Usopp has a buncha ammo and a stick.
Forgive me if I forgot anything. But these are a few reasons why Nami is stronger than Usopp
