Here's some stuff that might help you with your problem.
1. Are you using just Luma or are you also using NTR CFW? If you're just using NTR CFW, remember to have the fefatesSE folder as well as the plugin folder in your SD card's root, and start the NTR CFW app. You'll know the cheat worked if the screen flashed green. If you're just using Luma make sure to have your folder name be the correct region and game number, as well as be in the correct folder (inside luma and titles, note that it's not 'title' but 'titles'). Also note that for both version you can't just put GameData.bin.lz in and call it quits. GameData needs to be in the GameData folder (inside the romfs folder if using Luma.)
2. How far into the game did you get into to see if the change had really worked? In the first two chapters of the game no one is going to be different because the characters in those chapters are different from the characters you actually get later on. So if you change Sakura in GameData.bin to be a villager, Sakura in chapter 1 is not going to be a villager because the game calls on a different Sakura. Since you also didn't change Corrin or Felicia (And presumably Gunter), then you wouldn't see a change until chapter (when you get Rinkah and Kaze).
3. Sometimes the game calls on extra characters depending on the route you're playing on. (For example, the Hana you get in Birthright and the Hana you get in Revelations are two different characters, with different stats as well.) For Birthright, these extra characters are stored in the A_HANDOVER.bin file inside GameData/Persons. I don't know these characters work exactly though, so you might not have to change them.