Audio modding
After a long time, Audio modding is now possible (for Warhammer 3 at least!)
Wwise
The total war games uses an audio engine called Wwise. This is a very powerful, but complex system. If you want to audio modding, you also need to get a basic understanding of the tool.
WWise Naming
The first thing to understand, there is no names in wwise. When a wwise project is compiled (saved for use) the tool converts all the names into id strings. This is why the game has a ton of files called 9484940112.wem. At some point they were named Karl_Eating_Goblins.wem and so on, but that name is converted (hashed)