Normally you think of a company with a CEO, the one who has the most power. The software company that I co-founded, we have three equal executives who make decisions, and it is comforting to have two people “watching your six."

To watch your behind, used in aviation as a warning by your wingmen.

Watch your 6 nighthawk, you have a bogie on your tail

We’re a bunch of data center geeks so having two sets of eyes watching you is much better than one. This concept is a bit too radical though for most people most know this concept as a Triumvirate.

A triumvirate (from Latin, "triumvirātus") is a political regime dominated by three powerful individuals, each a triumvir (pl. triumviri). The arrangement can be formal or informal, and though the three are usually equal on paper, in reality this is rarely the case. The term can also be used to describe a state with three different military leaders who all claim to be the sole leader.

On the other hand a a Co-CEO is more common.

Co-CEOs: Are Two Better than One?
April 2 2012 by Russ Banham
Two for the Road: The Rise of Co-CEOsAre Two Better than One?
“Co-CEOs are ideal in many situations, especially when the executives provide oversight of each other’s actions and have complementary skill sets,” says Stephen Ferris, a finance professor and Rogers Chair of Money, Credit and Banking at the University of Missouri’s Trulaske College of Business. Ferris has studied the efficacy of the co-CEO model and argues that it is a highly effective way of running a business. “Co-CEOs are ideal in many situations, especially when the executives provide oversight of each other’s actions and have complementary skill sets,” he explains. “It’s actually a very successful model.” From his research on more than 100 shared-governance examples,

Reading CNET news latest post on Microsoft CEO Hunt, it says that Mulally and Nadella are leading candidates ahead of others.

Ford boss edging out Nokia's Elop in race to replace Ballmer at Microsoft, report says

New reports suggest Ford's Alan Mulally and Microsoft exec Satya Nadella are ahead of rivals including Nokia boss Stephen Elop in the race to replace Microsoft CEO Steve Ballmer.

Everyone is focusing on who is the one, but maybe Microsoft should have two CEOs. If Microsoft had Nadella and Mulally the two combined could easily outperform Ballmer’s one CEO performance.