It seems that a lot of people arent installing this correctly, thus causing a lot of desyncs, and runining the games, so imma do a li'l tutorial on how to install it properly.
First, you have to download ALL 3 packs from the workshop:
Then, you have to download ALL 3 mods again from google drive and overwrite the workshop ones in the data folder(X:\SteamLibrary\steamapps\common\Total War Attila/data)
I made two guides ages back when it was first released on Steam that might also help. It only covers 1 pack, instead of 3 but the principle and way to do it is the exact same.