The shotgun is a red-headed stepchild in the "practical" sense IMO of course. Meaning it's use with a pistol AND a rifle on a single stage has always seemed a bit goofy >to me<...
I own and shoot all of the above but the "scatterblaster" is for food gathering and occasional round of sporting clays. Shooting practical pistol and rifle alone or together on a course of fire is where it's at.
I "guess" what I am trying to say is, in the purest practical sense, a rifle and pistol have real history together. We added the bird buster in that mix for reasons I am not overly enthusiastic about. So there