I tend to agree with the authors, but also with our Woodstock poster here. The intense burner type leader can have major impact (and major failure) but history, I think, or at least what sticks out in my mind, shows that the quiet focused leader has had more impact. Consider World War II. We won the war and the peace thanks to the studied plans and executions of Gen George C. Marshall, as opposed to Gen George Patton, who inspired ( with a good deal of hype from the press and later Hollywood) us with his stolid determination. It would be an interesting exercise to look to the founders of the United States and try to figure out who was what type of leader nad how in conjunction, were some the most brilliant of all time. For example, Hamilton, flouty, bombastic, scheming, and eventually prematurely dead, but look at his achievments. He's a tough one to categorize this way.
This is or should be an incredibly interesting discussion though you'll probably get a number of bombasts defending themselves.