Has there really been a successful long-running CWC that sought to function like Ted or Song with mainline planes and longer routes?

Perhaps a more interesting question is how airlines relate to their regional partners, perhaps with a compare/contrast of ownership models. e.g., AA as a long-time owner of AE, whereas UA has many regional partners that it never owned. Plus you can study the evolution of the AA/AE model, as outside partners are now operating under the AE brand, even as AA continues to own a lot of the planes ("Envoy Air").

The other current case study not mentioned here yet is AC/Rouge. That includes TATL flights. I'm flying it this summer. (Hey, a bunch of award seats together on peak days...I can't complain too much.)