It's not clear why this would change anything.
Said individual is still presuming to know who is a servant of God, thus presuming himself to know God.
So adding a few degrees of service, or other instaces of mediation, doesn't change anything.
For one, I'm not the one making an argument for my own humility or lack thereof.
Theists, however, do tend to make a point of their own humility.
Secondly, I did not actually say that
Such persons who claim to be able to discern "This is from God, and that is from the Devil" are not humble;
such persons who, in public, claim "This is the truth about God" are not humble.
I do note that it brings confusion (sometimes a lot of confusion) to listeners when someone claims to be able to discern "This is from God, and that is from the Devil" or "This is the truth about God."
In fact, the Buddha's first sermon after he attained Awakening was "I am the rightfully self-enlightend one" to the first person he met on the road. The person looked at him in confusion and walked away.
After that, the Buddha (with some encouragement from the Devas) decided that proclaiming his qualifications put people off and was counterproductive to his efforts to enlighten others, and after that, he didn't do it anymore, but changed his approach to teaching others.
I wonder if theists would be willing to take this lesson from the Buddha ...