It seems like they are just trying to replicate the old musket/smoothbore load known as "buck and ball". Basically, wad over powder, then one large, bore-sized round ball with anywhere between 3 to 6 OO buckshot pellets on top and around the main ball. Then a wad to cover the entire works.
Thing is, traditional 'buck and ball' was a very effective load because they were tailored for use in large caliber smoothbore long guns and a good quantity of black powder can be used without worry of increased chamber pressure upon firing.
THIS, however?...................I think I will stick to my PROVEN lead flat-point and JHP loads for effective threat-neutralizing in my large bore handguns. By the way, doesn't Winchester already do this with their PDX-1 line of .410 shotshells made specifically for use in the Taurus Judge revolver? A single slug with 3 to 4 'Defense Discs' on top of it?