A supermodel is the model that another model draws its animations from. For example, player models draw their animations from a chained series of supermodels with various shared and unique male/female animations. When the game tells the model to play a specific animation, it checks if that animation is included in the model, if not then it looks at the specified supermodel and checks it for the animation (and further on, if it also references a supermodel itself, like for players). "Super" in this sense just means "above", referring to the fact that the model with the animations is higher up the chain in terms of priority.
The original C_Terentatek model has unique animations. For the scaled versions I just imported geometry only, scaled up the scene, changed the name of the AuroraBase, changed the animation scale value to match the world scale change, and then changed the supermodel from null to C_Terentatek. Thus the scaled versions have no inherent animations themselves, they rely on the original model for those.