I thought you already had a Staffordshire Bull Terrier. Sure the two will get along? They seem to be doing fine. The Staffie is a female, and is about 2 years old, so tolerates the Rottie's bullshit for now. They may very well have it out at some point where one will establish dominance over the other, and things will settle down to a new norm. They may never have it out, with the puppy always assuming it's bottom rung of the ladder. We shall see.