Fans of horse's-mouth success manuals can pick momentarily between the counsels of two of America's biggest operators: Henry Rogers, of Hollywood's Rogers & Cowan (below), who has flecked for royalty as well as the reigning stars; and Mark McCormack, of International Management Group, who's made the fortunes of many an athlete (starting with Arnold Palmer) and today also markets Tiffany's. For anecdotage, Rogers wins hands down: all too many of McCormack's yarns discreetly involve unnamed clients and CEOs; some are second-hand, even legendary (Picasso, Ray Kroc), others aren't worth telling (an associate's foot-in-mouth mention of the competition). The actual advice is a mixed bag of common sense and caginess--leading off with ""reading people"" and working around to time-management. And a goodly portion is more applicable to McCormack's special circumstances than to routine business situations--including such a bona fide time-saver as ""do the things that everyone has to do at the times when everyone else isn't doing them."" But, like Rogers, McCormack is no fool--on sizing up situations, conducting negotiations, or ""diversifying experience."" (""How can we fairly implement an event in which we represent the sponsors, the players, the television rights and the governing body? The answer is. . .very carefully."") So it the book doesn't quite live up to its title or to McCormack's reputation--in unconventionality or inside-dope--it does have its points to make about getting a strategic edge.