The last two graduates from my program are working primarily as EM attendings. Most of us went into these programs basically with the mindset that it was EM first, and FM as a back up.
The EM components are reduced, I think we do something like 6 less months of EM than my colleagues in the straight EM program. I will agree with that. On the other hand, we get additional training in specialty fields (like ID, Derm, GI, etc) that the EM program does not get. Not everyone may agree, but I feel as if the FM component of my program will make me more rounded and able to give more definitive care in the ED.
The mission, at least at my program, of the combined program is to train rural physicians. Doctors that can handle every day primary care, but also able to give care when the crap hits the fan. Do I think I'll be able to work in a trauma center when I graduate? Sure. Why? Because trauma is so algorithmic that a 2 day course certifies you to handle trauma. (Just like taking ACLS prepares you to run a code, but you have to take it for what it's worth).
Applicants to EM/FM have to decide what they want to do with it before hand. If you are really concerned with the lack of training on the EM side of it, then maybe you should just be doing EM. But I can tell you pretty much right now, that most graduates do EM primarily. We actually do have a study ongoing right now though, to follow up with graduates from the programs, to see what they are doing with their training.