This book was briefly in vogue in the 1990s. It was popular because nobody had done anything like this before, not because it was done well. The idea of a 20th anniversary reissue is based on the fact most people are too young to remember it or had forgotten how inept it was.
As a history book it is shallow, though not entirely without interest and mostly accurate. As a leadership book it is pretty trashy. There are plenty of vaguely stated aphorisms that are pretty obvious and can be found in any book on leadership. All of them are totally fake, of course. Roberts made a lot of money by attaching his own mediocre insights to a major historical figure; the best that can be said is that he doesn't pretend that any of this twaddle is genuine. However, to keep up the "mystique", he uses the word "Huns" for "you", "they", "subordinates" and pretty much anything else. This gets pretty tiresome pretty quickly.
Let's not forget that, within months of Attila's death, his empire was overthrown by an internal rebellion. If your goal of leadership is to create a structure that is only held together by the immensity of your own ego, then Attila might be a good role model for your business career. You could be the next
Robert Maxwell.