Lets put this another way. It seem that the question of the loyality of the blacks in southern service seems to be based in the fact that slaves being slaves did not have free will, and because of that status, therefore could not possibly be loyal because they were forced into the southern service. Would that be a correct assumption? That seem to be the root reasoning of yours and Jims responces and you may be right.
But, If that is a correct sumation then what about the conscripts of both southern and union armies in 1862? Men who didn't enlist at the first Bugle call and who didn't enter into service until they were made to? What about the Confederate soldier who deserted to go home and take care of his starving family and who when found was shot for his desertion. Was he loyal or disloyal? He was certainly force to be in the army and recieved the most severe punishment for leaving.
What about all the men who did not volunteer for service, but were drafted into service in that War, or World War I, World War II, Korea, Viet nam, up to our present day voluteer army? Were they any less loyal in their war than the enlistee were simply because they were enlisted by a legislative law and forced into service the same as you might say the slaves were? I remember in 1969 that enlistee in the army carried and "R.A." (Regular Army) serial Number while draftee's serial numbers started with "U.S." (United States) as a method of telling the difference between the "loyality" of the two servicemen. Is that what you are talking about that the slaves could not possibly be loyal because they entered the army under duress the same as a draftee?
I think that you would have an argument over those old vets and their service if you were to question their "loyality" simple because of their enforced "Draftee Status". I will say that I knew of many such draftees in the army in the late "60's and early "70's who did not care about anything of why they were in the army except getting along as easily as they could and getting back home alive. I guess they were not loyal under those terms. But some were D--- Good fighters and soldiers who earned their decorations and some didn't come home. Some were men that anyone would have been proud to have served with. But they still were forced into their situations by people who held authority over them.
So just how do you measure loyality? And how do you say that someone doesn't have it simply because of their status of how they entered into their service?