“In other words, there were no orders to commit such atrocities”
‘In other words’ the Union army leadership tolerated war crimes.
You attempt the evade that fact by pretending that war crimes only existed if they were ordered.
Lets see you produce a record of the court martial of Union troops for committing arson and theft and rape to demonstrate that war crimes were not tolerated by the Union commanders.
But of course arson and attacking the civilian population was the well documented strategy of Sherman in particular, who at least had the excuse of being insane. His superiors who knew what he was doing bear a greater guilt.
If there was a well documented strategy, then produce it.