I guess to your point Trump should have know how corrupt the FBI, NSA, CIA, DOJ was.
He confidently promised
only the best.
Now, we are told he was ignorant.
But wise people recognize they might not know everything if they're an outsider. Wise people would also recognize the corruption in these agencies.
Ergo, Trump is not wise. He was an ignorant fool, bragging from a place of ignorance.