Yes, I see your point. They always do teach modern military to fight against guerrillas, which is essentially what many “insurgents” abroad are and what the Americans were in the fight against the British. So that’s reasonable.
The South has a lot of mountains and difficult terrain, so that’s also reasonable.
Still, it’s pretty bad optics. NC is a blue state (thanks to Asheville and all the retired professors), so it’s not an attack on the South in general. But I think they should have done this in Upstate NY, famous home of Revolutionary War guerrillas.
The counties listed are very red and the Army has been conducting exercises, some really large, there since before WW2.