Yeah, isn't claiming Sherman is a better General like claiming that Patton was a better General than Eisenhower?
Yes, he was, but Eisenhower had different responsibilities.
Besides, it was Jackson that was the military genius.
This. So. Much. This.
Lee never lost a battle with Jackson "advising" him. Lee never won a battle after Jackson died. Lee butchered many, many more Confederates then Sherman ever did.
Lee and Sherman had similar responsibilities. Both commanded Field Armies. Lee commanded the Army of Northern Virginia. Sherman commanded The Army of the Tennessee and later the Military Department of the Mississippi for the Georgia/Carolinas Campaign (three Field Armies). Neither were overall military commanders of their respective sides (Grant succeeded Halleck, and Jefferson Davis acted at Chief of Staff or Commanding General of the Confederates.)
I do so Highly Recommend Victor Davis Hanson's book
The Soul of Battle: From Ancient Times to the Present Day, How Three Great Liberators Vanquished Tyranny.