Attractadore
Chieftain
So this is a mod i made. It uses a "dummy" bts directory (as all other mods). The directories contain only the changed files (if the a file is not present, the default one is loaded). So if you want to add a unit, you create your mod folder, you copy all the files you need (unitinfos, unitatrdefinesinfos), paste them into the same directory (i.e. your_mod_dir\assets\xml\units\) and then edit them. Same goes for civilizations, buildings, etc.