A good team could be Pikachu for its popularity and electric type moves which are useful in many situations. Charizard as it's a powerful fire type. And Bulbasaur which can cover different types with its grass and poison attacks. These three are classic and can handle a lot in the story.
The story of Pokemon Fire Red is about a young trainer's journey in the Kanto region. The trainer starts with a single Pokemon and travels across various cities, battling Gym Leaders to earn badges. Along the way, they encounter Team Rocket causing trouble, like stealing Pokemon. Eventually, they aim to compete in the Pokemon League and become the Champion.
For the story mode in Pokemon Sword and Shield, Sobble, Grookey and Scorbunny are great starters. Sobble can turn into a powerful water - type, Grookey into a strong grass - type and Scorbunny into a fire - type. They can cover a wide range of types as they evolve.
In a Pokemon Red join Team Rocket fanfic, the main character could be a disillusioned trainer. Maybe they've lost a few too many battles and are looking for a new way to gain an edge. Team Rocket seems like an alluring option. They join up and are immediately thrust into the world of illegal Pokemon trading. However, they soon meet a friendly Pokemon that shows them kindness despite their new allegiance. This makes them question their decision to join Team Rocket and they start to think about how they can use their new position to actually help the Pokemon instead of harming them.
Naruto himself would be a great addition. His determination and ability to never give up would translate well into being a Pokemon trainer. He could bond quickly with his Pokemon. Also, Kakashi would be good. His intelligence and strategic thinking would help in planning battles. And then there's Shikamaru. His lazy - but - brilliant mind could come up with unique battle strategies using the Pokemon's abilities.
One of the best team stories could be a team centered around a powerful Charizard. You start with a Charmander in the early game, train it hard, and it evolves into Charizard. Alongside it, you have a Pikachu for its speed and electric attacks, a Lucario for its strong fighting and steel type moves, and a Gardevoir for its psychic abilities. This combination can cover a wide range of types and strategies, making for an interesting team story as you progress through the game, facing various challenges and trainers.
Well, in Pokemon X for the story, I'd say start with Chesnaught as it's a solid grass type. Then add Lapras which is very useful with its water/ice typing. Charizard is also a great addition for its power. Sylveon can be a good support with its fairy type moves. Garchomp is a strong attacker with its dragon/ground typing. And finally, Ampharos which has some great electric moves to help out.
A possible best Pokemon Sword team could be built around Duraludon. It's a steel - type with high defense and attack. Add Centiskorch for its fire - type power and long - range attacks. And Boltund, a speedy electric - type. Their story could be that they are on a quest to find the rarest Pokemon in Galar. They face many tough battles, but their combined strength and different types help them get through. For example, Duraludon can take on physical attackers, while Centiskorch burns down grass - types and Boltund zaps water - types.
One great Pokemon Sword team could be centered around Cinderace. It has amazing speed and attack stats. Add Zacian for its power and cool design. Then, there's Dragapult which is super fast and has great special attack. This team's story could be about rising through the ranks in the Galar region. They start as a group of misfits but quickly become a force to be reckoned with, facing all kinds of trainers and challenges along the way.
Well, I'd say for the story in Pokemon Shield, you could go with Sobble, Grookey, and Scorbunny as your starters. Then add some like Duraludon which is a Steel / Dragon type and can handle a lot of different types. Also, Grimmsnarl, a Dark / Fairy type that's quite tough in battles. And Appletun, a Grass / Dragon type that has some useful moves and good bulk.