Nami vs Hodi would be better because she was weak when they fought Arlong. Her defeating Hodi, basically Arlong 2.0, and overcoming her past ties with the Arlong pirates would be a great read. Zoro vs Hodi has no story benefit.
I'm positive we will see Nami vs Hodi.
Seeing Nami, considered one of the weaker Strawhats, taking on a demon like that would show just how much the Strawhats have improved in the past two years.
Also, Usopp vs Decken.
Zoro will go against that venomous Octopus fishman. He ALWAYS goes against the swordsmen and ONLY the swordsmen.