What savings? Uniforms still have a cost, whether it be one style or 5 (don't forget the Coast Guard!). The services still operate under one commander (POTUS), and even cooperate with each other, through appropriate channels, whenever needed. Each service has a different basic mission to perform, and would still need to do that mission, even if "unified".
There WOULD/COULD be major problems, however. Can you imagine a former Air Force member, trained in maintenance of the KC-135 tanker aircraft, being assigned to an aircraft carrier, which has no large aircraft? How about a Army infantryman being assigned to a ship? (Compared to a Marine assignment).
A number of years ago, I witnessed what happened when the tankers were re-assigned from Strategic Air Command (SAC) to Military Airlift Command (MAC) -- people who had never worked on SAC aircraft were assigned to the "new", previously SAC aircraft, but knew NOTHING about the aircraft they now had to work on! (Yes, both SAC and MAC had "large airframe" aircraft, but after the airframe, everything else was different!) It takes years to learn the intricacies of an aircraft type, and mixing them was a GIGANTIC problem. They ended up maintaining different specialties, based on aircraft type, to avoid problems.
Somebody might say that, with additional training, "unified" services might work better. I have read on the BB, from one of our Canadian members, that Canada has a "unified" military service, and that it is a shambles. (My words, not his). Why try to do something that has failed elsewhere?
Bill :godisgood: