Luffy vs BB - the captains, and extremely obvious
Zoro vs Shiryu - swordsmen, also extremely obvious
Nami vs Lafitte - navigators, and also noble burglar vs corrupt cop
Usopp vs Van Augur - snipers, also extremely obvious
Sanji vs 10th Titanic Captain - no one else really fits with Sanji for now. The 10th Captain should be really strong in order to justify the mystery around him
Chopper vs Doc Q - doctors, and also extremely obvious
Robin vs San Juan Wolf - we don’t know Wolf’s role in the crew iirc, but Robin being able to create giant versions of herself means that she could be the best fit to take on the giant
Franky vs Avalo Pizarro - we don’t know Pizarro’s role in the crew, but iirc he does some have mechanical gauntlets on him.
Brook vs Vasco Shot - no one else really fits for Brook right now
Jinbe vs Burgess - both helmsmen, and also martial artist vs wrestler
Yamato vs Catarina Devon - women
Zoro vs Shiryu - swordsmen, also extremely obvious
Nami vs Lafitte - navigators, and also noble burglar vs corrupt cop
Usopp vs Van Augur - snipers, also extremely obvious
Sanji vs 10th Titanic Captain - no one else really fits with Sanji for now. The 10th Captain should be really strong in order to justify the mystery around him
Chopper vs Doc Q - doctors, and also extremely obvious
Robin vs San Juan Wolf - we don’t know Wolf’s role in the crew iirc, but Robin being able to create giant versions of herself means that she could be the best fit to take on the giant
Franky vs Avalo Pizarro - we don’t know Pizarro’s role in the crew, but iirc he does some have mechanical gauntlets on him.
Brook vs Vasco Shot - no one else really fits for Brook right now
Jinbe vs Burgess - both helmsmen, and also martial artist vs wrestler
Yamato vs Catarina Devon - women