Yes, he was a know-it-all but he didn't write all of the books. My recollection is that he was coauthor or editor only for at least a couple of the books.
Ed is of course correct, but in my mind I usually associate these books with the other author. The excellent book he did on NH steam power with Swanberg is a fine example.
Again, adverse comments on writing ability aside, I still would seek out each and every one of Stauffer's books- if for the only reason that they will so often turn out to be the only sources of information on a given subject.