If anyone must hold such a title, it would RE Lee, who lost as many battles as he won (Grant won all of his), and when on offense (i.e., Antietam, Gettysburg) lost more of his army (percents) than Grant.
And unlike Grant, who never did, Lee was always pleading for more men & materials from a population which could afford neither.
But Lee was a great general, just as good as that other great Virginian, George Thomas, the Rock of Chickamauga.
Michael.SF.: "General Sherman as the highest decorated War Criminal to not be charged."
Sherman committed no "crimes" against Confederates that Confederates had not already committed against Union citizens.
And unlike Confederate armies which grabbed every Northern freed-black they could for sale in Confederate slave markets, Sherman set many thousands of slaves free.
He never had to, as he had as many as he needed.
I think Grant’s western river campaign was never really surpassed; careful, efficient, effective strangulation of the Confederacy along the Mississippi was not as spectacular as Gettysburg, and since it was far away it just didn’t seem to get the press and attention, but once the Confederacy lost the west I think the argument could be made they could never have won without actually taking Washington.