I imagine that we can also speak about others. Well, this is only an idea which I thought with my gilrfriend and some friends, i am not saying that it is the truth, it is only one option.
Monet for me is always a candidate. Yeah, I know that maybe she is dead, but this is one piece and nobody dies (Specially look what happened in the last manga chapter jajaja). She fits in nami robin pattern. Ex enemy, intelligent and studies, she was damaged by a knife like nami when she hurt herself and robin when crocodile hurt her in the chest. She has a female family like robin mom and nami mom and sister, she had to travel alone through the world. Her first full screen was so similar like nami and robin sitting on a place. And she is the last one who can betrayed luffy and left the crew. Nami betrayed luffy and she went out of the crew by arlong, robin again by lucci and monet had a sad past because doffy said it and she was the one hasnt enjoyed of a full past story like DD pirates. Plus the nothe which read chopper and nowadays no one said anything about that. She could be the lookout, in the crew nest, oda put in an sbs a telescope. Is the perfect place for her by her studies.
Jimbe has already joined. But it was so clear or i think so. He was called a monster like chopper and zoro. In once time he was tied like zoro and chopper. They three have a full japanese pattern (Tanuki, Samurai, Sumo fighter and kimono). They three helped someone before metting luffy. They are full (near) fighters. The first stop of luffy in a new sea. They joined after luffy met a "fat" enemy (After alvida he met zoro, after wapol chopper joined, after big mom jimbe finally joined). And people used to think bad things about they three, zoro a bad person, jimbe fisherman story, chopper is a freak.
I have doubts with the third and fourth patter, as i said in other post, making comparations in one piece is so ramdon and difficult. Maybe i am wrong, maybe i found something interested, but well, only god knows. But if I must choice. Bellamy and momo...
Bellamy fits well with franky and Usoop. They three were betrayed by someone of trust (Kuro, Lucci, Doflamingo) Their enemies lied and the whole island believed them (Kuro work in the island, lucci work in the island, dolamingo as the king). They three were the captain of a gag and they had a ship story. Now Bellamy is learning doing flags (this is a idea that i saw in
@Tokiro Oumaga theory) and luffy doesnt know how to make flags. Of course that ussop can make flags, but he also know how to fix a ship but someone better appeared to take that role, franky the ship master and bellamy maybe the flag master. They three had a bad thing in the face. Bellamy scar, Ussop nose, Franky triple chin jajaja. They also were in once time an enemy of luffy. Bellamy always had a dream, the esmerald town and being in a famous pirate crew, so he had something to complete. Remember that all the fleet of luffy accepted being part of the fleet, but bellamy doesnt, and he took the vivre card by some reason and he had to do something before. Then we saw him in a cover learning flags and drawing luffy crest. For me this is so strange
Momo fits with sanji and brook pattern. They love women, they were formal clothes, they three had a problem with a famous enemy and they couldnt do nothing but luffy decided helped them. Sanji first with krieg and them with judge, brook with Moria and the shadow, Momo with lord kaido. They suffered a change in their bodies, Sanji ADN and right now again, Brook rebirth, Momo with shinobu powers. One more thing, is thad Momo now is an adult, and he could be a "true second oden instead of yamato willing", Momo maybe will travel first with someone and in the future join in luffy adventure. Brook past have a lot of strange things, maybe if his past is full showed, we would create a better fourth pattern. Momo had a fake father and sanji also had a fake father. Kin and Zeff. Maybe brook is hiding something, maybe yes, maybe i am wrong jajaja
Of course that I also find good things for Yamato, Carrot, Caribou, Caesar, Kuma, Vivi, Pedro, Marco, Law and X drake. But for me, there four are the most problably future crew members, but of course i cant say that it will happen yes or yes. Is so difficult making a full pattern, in one piece lives so many things in the same level, i dont know who will join finally.
Anyway, I think if Yamato joins, I repeat that she also had good pattern benefits. First she had to join in another crew like oden did. I think Kid or Law being the "new shirohige", and the join luffy. But I think that Momo will make this travel instead of yamato. Right now the big problem that I find in yamato and carrot are two things. Yamato being the "true protector of wano and Luffy reaction about Oden diary". And Carrot with the problem if pedro is or not dead and right now she is not a main character.
Also, I will say it forever, we musnt forget vivi. She is a good candidate always. Yeah, maybe other candidates are better, of course, carrot and yamato are better than her for the moment. But she will be always vivi, a "nakama" of luffy, and is a tittle that she only had. The problem with bellamy is the fact of his full name, but knowing that all pirates in DD crew had a special name, maybe bellamy is the same. And remeber that ussop is sogekin and Franky cutty flang. Maybe bellamy is only a fake name. But is a problem. With Monet the same problem, she is alive or dead?, we dont know, this is one piece, and Oda didnt draw the DF being again in another fruit like smiley. And nowadays her sad past and the note of chopper are still in the air. With tama the problem is a big one. She is not an adult and it will be weird, unless shinobu use her power, like momo.
But again, the main issue is the next, right now the favourite is yamato.
