The 24th Arkansas had a chief cook and a couple of under-cooks on the rolls, but those men appear to have been white. What makes the 33rd Arkansas situation unique is the fact that their cooks were slaves, but were regularly enrolled in the Provisional Army of the Confederate States and carried thus on the muster rolls. This was totally unauthorized, and I suspect that the company commander was simply unaware of the regulation.

From everything I've read, colored servants were ubiquitous in Confederate camps. They were an integral part of Southern culture, so it's no surprise that they would also be present in camp and in the field. The 33rd Arkansas muster roll, however, is the only instance I've seen of an Arkansas regiment actually mustering them into the service and carrying them on the rolls.