I read it and was surprised by the footnoting. Not that many sources are noted (that's not to say that Broers is unfamiliar with the literature), mostly Napoleon's Correspondance. Often he'll make two claims in a sentence and only one, the less controversial one, is referenced. Nevertheless he does make an effort at nuance (unlike Dwyer) and at least give Napoleon's life story an "arc". Broers only gets to "hubris" after 1809, which is an improvement over the general run of Napoleon biography's who put it at 1805.
I don't think Broers is an expert on military affairs as most descriptions of battles. etc. are pretty much what you'd get in an encyclopedia entry.
And he does mention the fear of cats.