As I recall (and somebody feel free to correct me if I'm wrong), ol' Stonewall Jackson had a brilliant track record of Wins on the battlefield; Lee's favorite and most trusted field commander; Lee's right hand...
Stonewall was shot in the Spring of '63, before the Confederates had even reached their military high-water mark...
Which either saved his Rep as a brilliant commander (because he wasn't around for the end-game) OR which may actually have cost the South their victory...
It seems unlikely that Lee would have engaged at Gettysburg if Jackson was still on the team...
And, of course, it was that defeat at Gettysburg, more than anything else, that turned the tide against the Rebs...
Had the Rebs not fought at Gettysburg, or had Jackson still been serving as Lee's second-in-command and been directing field-operations at Gettysburtg and fought the battle a different way, then...
History might have taken an interesting turn in another direction...
Jackson performed brilliantly throughout all or most of his service - on both sides...
Like Lee, worthy of respect, regardless of The Cause...