If anything, Buffett/Munger proves the rule: on the org chart, there's no question that Munger reports to Buffett. In practice Buffett isn't trying to call shots day to day, so Munger is functionally in charge of the org, and when he succeeds to the Chairman & CEO title, nothing will really change, but the fact that he's not fighting for a Co-CEO title is a positive sign.

Munger is 99 years old, he's 7 years older than Buffett. They have been partners for almost 50 years. He's not going to succeed anyone!