Yes, and I think that the bottom line is that the Confederates used whatever they could get for buttons. Particularly for the early war homemade uniforms and for field replacement buttons later in the war.

I have one example of a homeguard soldier recounting that he had finally gathered enough brass buttons to replace the existing civilian buttons on his uniform. This was in early 1865. It would appear from his writings that these were a mix-match of whatever brass buttons he could gather, one at a time. I would not be surprised to learn that more than a few CS uniforms had many different kinds of buttons on the same uniform.

As to the State buttons, most of these were used on pre-war (and postwar, too, btw) militia uniforms, of which many were worn into the war in the early days. Many were also issued to the pre-war State armies raised in late 1860/early 1861 in anticipation of the war. (For example: the Army of 10,000 in Mississipi and the Army of Alabama). I don't know the history of Tennessee's militia and State forces well enough to say much about that, but perhaps these were very small and that could explain why there are so few Tennessee state buttons.