Well it's by definition not exceptional if all comparably placed CEOs are performing the same. :) But, nitpick aside, I agree there's a flaw here, since it doesn't differentiate between the CEOs performing "to spec" or under spec. Though, when you get to have an agglomeration as big as a large multinational, there have to be serious missteps or moments of brilliance to really differentiate a bad and good CEO. Otherwise, it's hard to tease out the relationship between company performance and market share, entrenched employees, quality of invested capital, etc.
Basically, companies are never actually identical so optimal moves for every company is going to be slightly different and this will compound over time. However, if each company is making the same moves then and getting the same results then none of them are making optimal choices.
Consider defense contractors may all be in the same market, but they have different contracts. Farms on the other hand are selling a commodity and are often mostly just at the whims of market forces.
