The resignation of Jim Balsillie and Mike Lazaridis has caused many business pundits to start writing eulogies for Blackberry maker Research in Motion, the company where they served as Co-CEOs.

Instead, we should take this opportunity to commemorate the beginning of the end of alternative top leadership structures.

For a while, their Co-CEO model was held up as a bold experiment in how the corporation of the future should be run. Similarly, I recently read a piece by Doreen Lorenzo, the president of frog, asking if we were entering a post-CEO world, where teams would take over from individuals at the helm of organizations.

The answer is no. Co-CEO, no-CEOs, multiple CEOs are all unique one-off experiments which rarely, if ever, succeed.

Look at RIM. Jim was responsible for directing RIM’s strategy, corporate development and finance. Mike was responsible for product strategy, research and development, product development, and manufacturing. And there’s no denying they had a great run, as a partnership and as a corporation.

But when the competition got grueling, difficult strategic choices were delayed or fumbled. When your competition is the iPhone and the Android operating system, can you afford to have corporate strategy reporting to one head, and product strategy and development to another? Can you have corporate development separated from product and R&D? Not separated by being in different silos of an organization – separated, unlike in any other company I know of, by reporting to different Co-CEOs.

Let’s face it – the dominant model for over 5,000 years of human history is a single leader at the top. Whether it’s tribes, kingdoms, armies, empires or corporations, having a single individual at the pinnacle of any organization chart is embedded in the human experience across time and across cultures.

Any form of documenting responsibility within organizations, from the tried and true RACI charting of the program management world to the more recent RAPID decision model put forward by Bain’s Paul Rogers and Marcia Blenko, eventually places accountability in the hands of a single individual. As the old English expression goes, “One head to wear the crown, one neck to get the chop”.

Our politically correct culture suggests teams are superior to individuals. In the Star Wars saga the Evil Emperor is bad and the Jedi Council is good. Certainly the popular media is quick to put evil intent on the single person at the pinnacle of some all-powerful entity.

But the real world is not so simplistic. Whether or not an organization is run by a wise King Solomon or an evil Lord Vader has nothing to do with whether ultimate decision authority rests in the hands of one, two, three or multiple people. The structural model is values independent.

The key is having an effective decision process, and having the right influences around the decision maker. Improving organizational effectiveness isn’t accomplished through unnatural changes in top management structure, but instead in surrounding the leader with the right teams, populated with the right individuals, examining the right questions in the right way. How this portfolio is designed and managed is critically important. As I argue in my new book,Who’s In the Room? How great leaders structure and manage the teams around them, organizational design should focus on configuring and managing these teams at the top of organizations.

In most organizations at the center of the portfolio of teams is always a single individual. Experiments like RIM aside, it’s how it’s always been and always will be. Leaders need to focus on making the conventional model work, not on coming up with radical deviations that are ultimately bound to crash.