To help you verify if a file you have found is legitimate (or to understand what you are missing), here are the actual technical details of Fire Emblem: Three Houses as it exists on the Switch:
If you find a Fire-Emblem-Three-Houses.rar that is significantly smaller than 11 GB, it is either fake, highly compressed (unlikely for Switch games), or missing critical audio/video files. Fire-Emblem-Three-Houses.rar
Some notable characters in the game include: To help you verify if a file you
: Your choice of House drastically changes the perspective of the story, offering hundreds of hours of replayability. it is either fake