Being from East Tennessee, I know the Russian Hogs...They are, like you said, very few pure bred Russians left, but we had plenty of them until around the 1980’s...
When I was younger, I ran a string of Plott Hounds and hunted them and black bear in the E. Tennessee mountains...
They would do tremendous amount of damage in the Smoky Mountains Nat’l Park...Rooting up huge amounts of ground...