Data Pack mob mechanics

Instead of multiple folders for mob variants, there could be one variants folder with one folder per mob inside. This would make creating new mobs through data packs easier, as the textures alone are difficult already. This brings me to my other idea: defining custom mob behavior in data packs. This alone would already be beneficial to data pack creators, but adding a way to change their behavior based on their variant or to set their behavior to a previously defined one without changing all mobs of the same type would be incredibly useful.