CEO material seems like kind of a myth to me. Politics and business isn't like sport - you consistently see people at the top of the top with track records that simply don't add up and simple aren't what landed them there. So there has to be something else that lands them there...
To be clear, of course there are CEOs who really are the best, but in my experience yeah someone being a CEO doesn't mean they're smarter or better at business or whatever even than the average employee at the company lol.