I'll be extremely surprised if Nami doesn't fight Devon given her "hobby" tbh. Both Nami and Devon are known for deception too and Nami tends to fight female opponents mostly at least.
I wanted Sanji to fight Devon with her tendency to murder beautiful women and collect their heads but imagine if Devon just so happens to have the head of Nami's biological mother, how brutal and tragic would that be? Sanji should send Devon straight to hell and incinerate her for what she's done but he can't fight women, even ones who literally mass murder other women, sigh.
Vasco Shot is a weird one but I think he is a fishman and if he does involve alcohol in his fights, he might make an interesting opponent for Jinbei? Assuming Yamato does join, there is the question who she will fight too. I think Chopper will fight SJW (lmao I mean San Juan Wolf ofc) but Jinbei is brilliant against larger, slower, heavier opponents so, he might be ideal vs SJW.
There is still the 10th titanic captain to be revealed who may just be Kuzan, we've not had a matchup for Robin yet here, but surely she won't fight Kuzan despite their connections? Only person who can take on Kuzan is Luffy really if they have to fight him or Zoro as well?
Oh wait there's Brook too, Brook gonna fight his "son/grandson" Kuzan?