to be fair regarding Hood's march on Tennessee...
in previous campaigns, the Rebs had hit Union communications (rail) very hard with frequent and highly effective cavalry raids. To the point where it tied down significant Union forces and delayed seriously Union advances.
http://www.amazon.com/Civil-War-Command-And-Strategy/dp/0029166357
this book basically considers the deep penetration raid the principal effective strategic move during the war by both sides, and seen in that light, Hood moving on Nashville makes a certain amount of sense as he couldn't stop Sherman's army any other way (after the pounding at Atlanta)
Of course Sherman himself was conducting a deep penetration on an epic scale. The Union Army when it left Atlanta did not leave any garrisons between Atlanta and Savannah (and didn't need to). The problem Hood had though is that Thomas was a better general than him, and more troops, better supplies, and understood that a frontal attack was suicidal (as it turned out to be at Franklin and Nashville). The other problem Hood had was that his concept of operations was completely outdated, because Sherman was moving too a new base and didn't need to keep communications with the railway to Nashville any more.
As to Early... his raid was designed to draw off troops away from Lee as well as clear the Valley. He did one, but he failed to significantly affect Grant's Overland Campaign.
So both of these great deep penetration raids by the South failed in their mission. They were supposed to force the Union to react to them, and stop the Union penetration of vital CSA territory. They failed because the Union had plenty of reserves to deal with them and continue their own efforts.
As to Sheridan... he was rash but highly aggressive. Grant gives him credit for the aggression and motivating force that outdistanced Lee in his retreat from Richmond and in getting in behind him and preventing Lee from continuing his retreat. So whatever faults he demonstrated in the Valley he more than made up for at Appomattox.
Jackson never demonstrated that kind of understanding of the vital elements of the war... finding, fixing and making it possible to destroy the enemy. He did a great job in driving the enemy into flight and away, but never successfully sealed the deal and won the decisive battle. Sheridan did.. at least according to Grant.
As to Sherman... he understood, better than anyone else including Grant that to win the war and break the Southern ability and will to resist required demonstrating Union power by marching through their heartland and destroying those things. He also outmaneuvered Johnston and drove him back, and demolished Hood, and ultimately was in position to trap and destroy Johnson again. Sources I have seen rank him as the General who best understood what it took to win.
While I admire Lee (he is a personal hero), he was the only one who really seemed to understand the strategic position of the South. It had to win a battlefield victory equal to Saratoga. It never could, but he understood the campaign objectives in his two moves North. I don't recall any other Southern General demonstrating understanding of that. Sure Gordan was a good corps commander (which by definition requires being able to handle limited independent operations). Early did a good job with what he had, and Hardee and Taylor both had a lot of potential.
But I don't think you will ever see them listed as Great Captains. I have seen Grant, Sherman and Lee listed as such