I do wish President Davis had listened to Lee more often. For example, Lee advised the President that the enemy intended nothing serious along the Atlantic coast, and that garrison troops could be collected in northern Virginia to threaten Washington while he crossed into Pennsylvania. Of course Davis did nothing of the kind, forcing Lee to contend with the entire force that the Federal government could concentrate upon him.
Why assemble troops in Jackson MS to simply to observe the fall of Vicksburg, when they could have employed to advantage elsewhere?