Well, in a fanfiction with Naruto trained by Tobirama, Naruto would be exposed to a very different teaching style. Tobirama was strict and no - nonsense. This could either make Naruto more disciplined or cause some clashes at first. Tobirama could also teach Naruto about the old - fashioned values of the ninja world that were prevalent during his time. This might make Naruto question some of the modern ninja ethics. And Naruto could inherit Tobirama's sense of duty towards the village on a deeper level, leading to him taking on more responsibilities in Konoha's development and protection.
In a fanfiction where Naruto is trained by Tobirama, Naruto might quickly become a master of water jutsu. Tobirama was a genius in water techniques, and he could pass on his in - depth knowledge to Naruto. Naruto would also likely learn more about the founding of Konoha and the Uchiha - Senju relations from Tobirama directly, which could give him a different perspective on the village's politics and history.