"All-American Mutt" Is a phrase that I use For myself as well. I'm part Scottish, French, Native American, Spanish (from Spain). My ancestors fought on both sides of the Civil War. Yep I'm a "Mutt" right out of the Great American Melting Pot.
I see where your coming from on the name, but I like Rottweiler. If you look up the history of the breed you'll find that the name Rottweiler comes from the city of Rottweil in Germany where the breed was used as a herding dog. Indeed Morgan instinctively wants to herd our goats, our ducks and geese (when they used to run loose in the barnyard), and my wife and I if we start going in different directions in the store. She tries to get my wife back where she belongs.