I can't offer scientific proof but it seems that Longstreet and Grant saw war more has a distastefull task that needed to be done and not has a romantic struggle. Certainly in post CW era contrast Grant becoming president , Longstreet becoming among other thing a US Minister (now we would use the term ambassador ) to the Otman Turk Empire vs Shelby becoming a druken witness at Frank James last criminal trial where he was aquitted. One gets the sense that many in the CW belong more to the romantic era of medevial knights vs a more modern view of 'we do what we gave to do to win and if we lose we adopt." Grant for example was willing to allow Afro-Americans to serve in his command and was willing to see Blacks has at least somewhat closer in legal equality to Whites in the post CW era. Obviously social change in the South including Mo took a long time to occur nut the CW and reconstruction was a crude step towards the racial equality that we now have. My thesis is a work in progress but I think there is something to it.
respectfully Yours,
Leonard