Stupid vs. Clever.

To Nietzsche,the noble Athenians were no match for the 'cleverness' of the 'plebian' Socrates. By using the clever technique of dialectics he made men who were MEN OF INSTINCT, question themselves, and so disarmed them.

So yes, in that sense, the powerful, the Masters are more 'stupid' than the 'clever', cunning slave/dialectician.
The powerful man is of the Warrior caste, and is no match for the priestly caste when it comes to 'cleverness'.

But cleverness is NOT noble;"Power is never ridiculous". [Napoleon]