Longstreet and Jackson were “modern” generals that believed in maneuver warfare, using terrain to you advantage, surprise and deception. To a lesser extent Grant was like that too.
They were also two generals who fit in well under Lee's leadership style, which was to give his subordinate commanders broad ideas of what his intent was and leave it to them to put those ideas into action. Longstreet and Jackson could do that. Ewell and Hill, not so much.