.... it's complicated((((If we're talking about the town, its "core" is the town file from MapObject. It contains paths to the fortress walls and the internal structure of the town in the Arena folder, to the buildings located in GameMechanics, to the arrows on the towers and their projectiles, as well as to the models for the map, which are probably also in the MapObject.
The unit's core is its characteristics, which are located in \GameMechanics\Creature\Creatures. The characteristics contain links to MapObject and CharacterVisual. As far as I understand, everything is done according to the "files everywhere" system, so the CharacterVisual folder will contain everything needed for the unit, including icons and text files.
The problem is with the bin folder - it contains all the models, skeletons, and animations. It's a pain to work with them, so try not to touch this folder at all. If everything is done correctly, nothing will break.
I'm still planning to help.... but yes, I'm a bit busy.
Yes, I understand. I apologize for being annoying ((