You could do it, but I think it would need more men. Stewart was actually given command of his own division and Bate's briefly at Rocky Face Ridge when Johnston needed three maneuver elements.
Hardee's corps began the campaign with 21,947 present for duty and Hood's corps was 21,310 present for duty.
You would have to take a division from Hardee and Hood each to avoid cannibalizing one of the corps (or otherwise completely reorganize the army, which Bragg had done to the army's detriment at Chattanooga).
So you would end up with a corps of two divisions - and as the campaign goes on, that two divisions is going to dwindle. Additionally, that corps will need more transportation, its own artillery, etc. A corps of 12,000 men does not have a lot of sustained power in combat. Additionally, the divisions of Stevenson, Walker, and Bate had pretty poor combat records. A corps made up of those divisions might not perform so well and might actually be detrimental to the army.
One of the reason's Lee was able to detach a light force with Early was, with combat had destroyed Johnson's division, bringing the Second Corps from 21,000 to 12,000 (a much smaller force) and forcing the creation of a new division (Gordon's) from Johnson's remnants and from elements of the other divisions in the corps (reducing them in size). Additionally, Early was able to get Breckinridge's division which was originally from the Valley.
My point, really, is that this should be done well before the campaign starts. I think these corps were too big for what was needed and should be smaller. Hardee might be capable of handling/organizing/maintaining a force that size; I doubt Hood was ( this is the criticism, really, that R.E. Lee had about Hood, that he was good on the battlefield and careless off).
When the AoT was reorganized that Winter, it should have been split into 3 corps, not 2, IMHO. The troops arriving when the campaign was to start could be fed into that structure (Polk's Army of Mississippi as the 4th Corps instead of the 3rd).
The point is that such an organization is more flexible. The number of troops remains the same, just organized differently. Sherman had more men organized into more corps, generally smaller than the Confederate corps, which he used to maneuver around Johnston almost at will. I am saying the Confederates needed speed and flexibility, which was restricted by the large corps they had.
The extra corps can be smaller than the others because it is designed to act independently and move fast under an audacious commander. It is not supposed to stand in the main army and slug it out toe=to-toe with Sherman. There really is no one in the AoT with the background required to say: "He's the one to command that!" Strangely, Hood might be considered above the others because of his eye for terrain, ability to make troops move fast, and sharp tactical eye; his other qualities make me doubt it. Forrest is another maybe, as is Taylor, but really the Confederacy is short on people with records of success in independent command.
So you might picture 3 infantry corps at around 17-18,000 and 1 at around 10,000. Put most of the cavalry with the main army under Wheeler and a division (Jackson?) with the independent force. That force will probably be operating to the west of the main army because it needs to threaten Sherman's LOC and draw off forces (IOW, doing in May what Hood tried to do in October).