That's essentially the same criteria used in America, and CEO would generally be considered an employee in America. Where does the CEO get excluded?

Your link notes that managerial positions carry certain exemptions, which is true in my country too, but that doesn't preclude managers from being employees.

Directors are generally not considered employees unless they also work as an employee serving some other function in the business. This appears to be true in Germany as well. Are we simply mixing up directors and CEOs?