Have you read the Overview chapter of the book? To achieve what you want you would not put controllers in the model folder, they go in the controllers folder. The default/index in the path refers to the file name and the function within the file name. So green/eggs/ham.refers to the green app, the eggs controller file (in the controller folder), and the ham function. Have as many controller files as you like, I use more than one.
The displayed URL you mention is achieved through routing, not by moving controller files. --
