you are absolutely right about each branch protecting it's own territory so I'm not sure it will happen either. But the structure I read proposed was the CG would be a component of the Navy just like the Marines are and even have an admiral on the Joint Chiefs. Also the CG hasn't been doing too well under the DHS which has enough to do at home without dealing with naval warfare, operation overseas, and other CG stuff in general. Besides the CG has always been a part of the DoD during time of war in the past. This just seems like a good time to switch and make it permanent.