Given the wide variation in quality among US healthcare organizations, and the fact that Kaiser has been consistently one of the better ones across most quality metrics, I think you are wrong and are underestimating the challenge involved in both running an organization of Kaiser's size and of recruiting an appropriate person for that role.

I do agree that assessment is less skill based at those levels, but that is largely because the job is not hard skill based. That doesn't mean the person doesn't matter or that they are interchangeable. No one but Steve Jobs could've turned around Apple for example.