Well nami doesn't need CoA since her attacks are basically elemental. The thunder can 1hko Caribou. CoO would be useful for her tho.
I recall Ussop also has elemental attack, and he already unlocked CoO, just need to improve.
Brook also has his ice sword, again CoO would be great.
Franky doesn't need to dodge shit since he is a tank, whether his laser can hit logia users, that remains a questions. Maybe he can replace his lacks of CoA with some seastone techs.
As for Robin, if her fishman jutsu involves using water at the surface of her palm, thenshe doesn't really need CoA if it's just to hit logias. But otherwise...
