Dual CEO'S - if anything a formula to be promoted

The recent troubles at Blackberry manufacturer Research in Motion seem to suggest that dual leadership can be damaging for an organisation (FT). But Rome had two consuls during its rise to dominance, and they were limited in their power to a tenure of one year. Goldman Sachs in the late 1970s and early 1980s had co-chiefs - and that was when the firm laid the foundation to its rise to dominance. The challenge for boards and shareholders is to make sure there is a deep bench of talent - a thing that is sorely missing in many companies, why else would a company ever look for an external candidate for any of its top positions?