I think the importance of female families has been proven throughout the history of the Thoroughbred. Long before the practice was dubbed "the Rasmussen factor," successful breeders of the past built their programs around the acquisition of quality broodmare bands. For example, Colonel E. R. Bradley acquired the legendary La Troienne and built one of the most influential breeding operations around her. Today, multiple strains of La Troienne are still highly sought after in pedigrees.
To me, any breeding theory that focuses only on stallions (such as Dosage) to the exclusion of mares is not a sound theory.