I think I know what you are saying, but you might not have it worded just right.Ok that diagram got a little messed up but what I am saying is is it possible to have two armies on one side with corps in it that wasn't avalible in tc
In one (?) of those Eastern Tenn. battles there were elements from 3 Union armies, Army of the Cumberland, Army of Ohio, Army of the Tenn., some grouping like that, all with their own army commanders. The only reason I remember that is from HPS Chikamauga game. It's been awhile, so I might not be totally accurate, but close.
As far as I know there was only one army commander on either side in GB, If the Army of the Cumberland came a knockin at Lee's back door at GB, that would be a different story and a What-if? at that.