It would be nice if they only took the top 4...but the UFC is also about showcasing popularity, even if it's not supported by top tier talent. So I don't see it happening in the near future.
I don't know that the casual fans would make the intuitive leap to follow a charismatic but C level fighter from the UFC to the WEC.
Minimally, I don't think TUF fighters who are not champions should appear on PPV's until they've won two consecutive fights. They can be showcased on UFN's, in my opinion.
All manner of men came to work for the News: everything from wild young Turks who wanted to rip the world in half and start all over again -- to tired, beer-bellied old hacks who wanted nothing more than to live out their days in peace before a bunch of lunatics ripped the world in half.
Dr. Hunter S. Thompson
The Rum Diary