Well, in the 3 - year training fanfiction, Naruto could also have some intense mental growth. He might learn more about the history of his clan and the ninja world from Jiraiya. This knowledge would not only make him a better ninja but also shape his understanding of his place in the world and his responsibilities.
It impacts the storyline in terms of character relationships. After three years of training, Naruto has new experiences and knowledge. His friends in Konoha might view him differently. Some might be in awe of his growth, while others could be a bit jealous. This can create new sub - plots within the story as they all adjust to the new Naruto.
In this fanfiction, Hokage Naruto might take Naruto to a special training ground. There, he could teach Naruto some of his own unique jutsu combinations. For example, he could show Naruto how to combine the Rasengan with his Sage Mode more effectively. This would give Naruto a huge power boost and also make him more confident in battles against tougher opponents.
He could meet other sannin. Maybe he stumbles upon Orochimaru who is on some secret mission. This encounter would be full of danger and Naruto would have to use all his skills and wits to survive.
He could learn new and powerful jutsus. For example, he might discover some unique wind - style jutsus that are not in the original series. This would make him more formidable in combat.
Perhaps he's been influenced by someone who gives him bad advice. For example, if someone tells him that natural talent is enough and training is overrated. Also, he could be dealing with some personal problems, like a conflict within his family or among his friends that takes up all his time and mental energy, causing him to neglect training.
In this fanfiction scenario, Naruto might learn unique chakra control techniques from Sarutobi. Sarutobi, being an experienced ninja, could teach Naruto how to better manage his large chakra reserves. This would lead to Naruto being able to perform jutsus more efficiently and with less waste of chakra.
Perhaps it's an old enemy who has a change of heart. This enemy could think that by training Naruto, they can make amends for their past wrongs. But Naruto, being cautious, denies the offer as he still has doubts about this former foe's true intentions.
Well, it could be that the three of them are training Naruto for a big upcoming battle. Temari focuses on Naruto's physical combat skills, teaching him how to better use his speed and strength in combat. Yugito delves into the more spiritual side of chakra, guiding Naruto to connect with his inner power. Naruto, under their tutelage, not only hones his skills but also forms a strong bond with Temari and Yugito. This bond might be crucial in future challenges that Naruto will face in the fanfiction world.
It could be due to the current situation in the village. There might be threats that required Naruto to stay. Tsunade, as the Hokage, had to consider the overall safety and stability of the village. So, she denied Naruto's request for the training trip to ensure he was available in case of any emergency.