One more thought - I remember reading in the INTJ profile that they tend to focus on developing one, or a few, areas of deep expertise instead of the broader approach of Perceivers. It also said that INTJs in particular are good at knowing what they are not expert at knowing. I wonder if this sort of thing could also apply to INFJs? Perhaps the IN-Js can be rigorous in evaluating their own credibility and apply a similar standard externally. Just a passing thought.