Originally Posted by
xioaxioa
I'm not all too big of a fan on using that same "black and white" system that everyone else uses. Example: Someone might say that Killer left Kidds crew or that Gin is still alive, while others would say that there is no basis for such words and disregard it as completely impossible. I'm more of a percentage kinda guy, so I make tons of different theories, most challenge each other, I then weight them and preach only the most likely. I also like to poke fun at people and tell them that there is a zero percent when it's more like 30 percent. Except the Killer thing, that was a 0%.
When it comes to this topic, Oda has always been straight forward on who would join with only ONE exception; that being Robin.
Chances of anyone joining this arc is a whopping less than 5%. Out of that less than 5%, rounded up, Kinemon and Monet have the highest chance of joining. Except Kinemon has a son and Monet would have more of an elegance to Law if she left Ceaser or Joker or whoever. Law can't join because he already made an Alliance with Luffy, thus ruled him out from being a candidate. Tashigi CAN'T join as it would forfeit her dream, and One Piece isn't about forfeiting dreams; her dream being to take away all the named swords from criminals. Impossible dream, but still her dream. Smoker on the other hand has always preached his own justice and never liked the World Government. He also always had trust issues, so nothing can hurt that department. The Dragon has the highest chance of joining and I don't even think he will join.
fan fiction does not a theory make. You'll know when a candidate is introduced, you will know.