All:
Did some genealogical sleuthing this morning, and here's my best guess: The James R. Ward AQM 16th Va Cav appears to be the same man as the James Ward, private company A, 8th VA Cav. The 8th Cav man's signature is a match for the 16th's Ward; and the 8th man has a CSR entry where he's serving as a qm. The 8th man enlisted for one year in 1861 and was wia in May 1862.
The 8th man enlisted in the Smyth Dragoons of Captain Thompson, at Marion, Smyth Co.
The best/only match in the censii is one James Ward, born 11-16-1813 Wythe County, died May 25, 1877 Smyth County. He was son of John and Jane (Davis) Ward. His brother Robert married Margaret F. Thompson, possibly a relative of the Captain Thompson above mentioned. This company A of the 8th had as Lt. William E. Peters, later colonel. Ward had family ties to the Bowens also. So it makes sense he was transferred to the regimental staffs.
In 1850 and 1860 Ward shows as a wealthy Smyth County farmer and slaveholder.
According to a post by a descendant of this Smyth County Ward, he was wounded in the leg during the war, and suffered from it till his death.
His family is buried in Morgan Cemetery, Smyth County, and I presume he is also.