I've been studying the wartime governorship of Zebulon B. Vance here in North Carolina, and recently I ran across something interesting that might be relevant to the question about a need for a Confederate Supreme Court.
The Confederate conscription laws were unpopular in North Carolina, and the State Supreme Court, according to some critics, had been leaning toward leniency in cases of desertion and resistance. CSA Sec of War James Seddon wrote to Vance on 23 May 1863, suggesting that Vance exercise his "full official influence ... to restrain the too ready interposition of the judicial authority in these questions of military obligation."
Among other arguments, in his reply of 25 May 1863, Vance pointed to this issue of the lack of a national Supreme Court:
"Whilst therefore it is my intention to make every possible effort to sustain the common cause, it is my firm determination to sustain the Judicial Authority of the land, the rights and privileges of the citizens, to the utmost of my power. By the action of the Congress, no appeal lies from the Supreme Court of a State to that of the Confederate states and the decision of the Supreme Court of N. Ca. when formerly rendered will be binding upon all parties."
(Joe A. Mobley, ed. The Papers of Zebulon Baird Vance, Vol 2, 1863. Raleigh: Div of Archives and History, 1995. Pages 170-174.)
Roy B.