The common MVC project uses "fat models", where each Model encapsulates it's respective business logic. Then the Controllers simply decide which methods to call from the Model, call other necessary services and manipulate the data to respond with a specific format; what you describe would be a "fat controller/skinny model", or maybe a service layer. You'll end up with some kind of Model either way, data structures will have to be defined somewhere.
I'm conflicted whether dropping the known patterns and established terms for this architecture is a good or bad idea, but it's interesting nonetheless. It's quite hard for a newcomer to grasp and implement MVC correctly, an architecture with clearer nomenclature and concepts might be helpful.
