I think perhaps feature stories in venues such as the Wall Street Journal (where both of these books originated) or Fortune or Forbes are the modern equivalent of fables: stories about larger-than-life figures involved in titanic struggles. It's just that nowadays the larger-than-life figures are corporations and law firms rather than giants and trolls. The overall structure of these books, though, is not so different from that of, say, Grimm's Fairy Tales. The corporate titans become locked in struggles that are revealed piece-by-piece to the readers, in a continuing cliffhanger that ultimately wraps up in a satisfying climax. Burrough and Helyar are certainly reporters and (to a lesser extent) historians, but they also have a novelist's sense of plotting and timing.
Barbarians at the Gate tells the story of the leveraged buyout of RJR Nabisco in late 1988. In fairy-tale terms this one would be the story of three suitors battling for the hand of the princess (in this case, the RJR Nabisco board of directors) so that they can inherit the kingdom (the multi-billion dollar corporation). It all works out to an excellent story, involving some of the most notorious figures of that period of Wall Street excess, including the firm of Kohlberg, Kravis and Roberts and the enigmatic Canadian businessman Ross Johnson. Though the authors do not set out to teach the basics of high finance, it's impossible to read the book without gaining some appreciation of the sheer beautiful complexity of the financial shenanigans involved in an LBO of that size.
Vendetta is Burrough's follow-on book, and it's a good deal weaker. The theme here is of the good king beseiged by ruthless enemies. Edmond Safra was a banker of Lebanese extraction who first merged his operations with American Express and then walked out to go back to private banking. It appears certain that Amex then hired some shady characters to spread false stories linking Safra to money-laundering and drug-smuggling, with tenuous links to the then-developing Iran-Contra scandal. (With Safra's death in a suspicious arson a few years ago, the rumors have inevitably resurfaced, but remain unconvincing). Burrough apparently decided that the story itself wasn't long enough, and the book is padded with a great deal of history and incidental detail that doesn't really contribute to any understanding of what happened. I would have also appreciated a more critical evaluation of the part that the press played in this nonsense; his pat dismissal of journalistic responsibility in the last few pages of the epilogue is rather thin.
Overall, if you like a good, fast-moving business story, Barbarians remains one of the best in the genre. I'd give a pass to Vendetta, though, unless for some reason you're researching American Express.