Well, as of the latest manga chapters, Yamato has indeed become a part of the Straw Hats. This decision brings new dynamics and adventures to the crew.
In a fanfiction where Smoker joins the Straw Hats, it could be really interesting. Smoker is a marine, and his sense of justice is quite different from the Straw Hats' view of freedom. At first, there would likely be a lot of tension. But as time goes on, he might start to understand their way of life. For example, he could see how they help the weak and oppressed in their own unorthodox way. He might also learn to be more flexible in his views of right and wrong, as the Straw Hats often operate outside the normal rules. And his combat skills would be a great addition to the crew, making them even more formidable in battles against stronger enemies.
In a fanfiction where Naruto joins the Straw Hats, the dynamic of the crew would change significantly. Naruto is used to working in teams in his own world, and his experience in forming strong bonds with his comrades would blend well with the Straw Hats' own sense of camaraderie. His ability to make friends easily would also help him fit right in. Plus, his shadow clone jutsu could be used for various tasks on the ship, like helping with repairs or keeping watch.
If Smoker joins the Straw Hats in fanfiction, the development might be slow. At first, he would struggle to fit in with their laid - back and often rule - breaking ways. But his sense of justice could lead him to find common ground. For example, he might see that the Straw Hats are fighting against corrupt forces, just in a different way than the Marines. As the story progresses, his character could evolve. He might start to see the world from the Straw Hats' perspective and become more accepting of their methods. This would not only change him but also affect how the Straw Hats view the Marines in general.
One possibility is that they gain a deeper understanding of Luffy's motives. For example, they might see his memories of making the promise to Shanks and realize how important it is for him to become the Pirate King. This could strengthen their resolve to support him even more.
The relationships will likely become more profound. For instance, Zoro might see Luffy's memories of believing in his strength even when others doubted, which could make Zoro more determined to protect Luffy at all costs.
Naruto is known for his loyalty and determination. If he joins the Straw Hats in fanfiction, these traits would strengthen the crew's unity. His loyalty would mean he'd always have the backs of his new pirate friends, and his determination would inspire them to keep pushing forward, especially in the face of difficult challenges. For example, when they encounter a powerful enemy, Naruto's refusal to give up would encourage the Straw Hats to keep fighting no matter what.
In the story of One Piece, the people who had the best chance of joining the straw hat group after the war with the country included:
[1. Vivi: As the princess of the Hezhi Kingdom, her strength and status are very high and she is a very valuable ally to the straw hat group.]
2 Sauron: As a swordsman of the Grass Hat Pirates, he is very powerful and has always dreamed of becoming a great swordsman.
3. Yamaji: As the chef of the straw hat pirates, his cooking skills are superb and he is good at using various potions and magic.
4. Nami: As a navigator of the Grass Hat Pirates, she has excellent navigation and observation skills and has a deep understanding of marine ecology.
5 Choba: As a doctor in the Grass Hat Pirates, he is good at healing all kinds of animals and plants and can use all kinds of drugs.
6 Brook: As a musician in the Hat Pirates, he has outstanding musical talent and can play all kinds of music with instruments.
These are the people I think have the best chance of joining the Hat Pirates. Of course, there are many other people who have the chance to become members of the Hat Pirates.