I think the ideas expressed in this site is great in terms of accuracy, but, as with most sources, not in precision. While it's true that functions contributes significantly(although it varies per trait) to such tendencies, the problem with generalizations on the whole and this is sort of obvious is that it does not account for all possibilities. There will always be some circumstance and/or perspective that halts a person from relating to one or many generalizations, as well as some circumstance and/or perspective that allow a person to relate regardless of not being said type. For example, we are not necessarily "more wary" when the function is lower. It's ok as a generalization, but it depends on the situation, the development and the condition of the person. Sometimes we are even less wary of it that as Inferior Fe types we act without consideration of social norms leaving more dominant Fe-types in shock. (or perhaps that's due to to having an undeveloped Fe.) I do appreciate how the author always write words that express the uncertainty such as "likely" "often", "may" etc. Anyways, in those mixture of perspective and scenario lies the importance of precision. Relative to other sources however, I think it's way more accurate. Focusing on the relation between the four main functions with the "other" functions, how Ne types perceive Se types for example, specifically helps precision in typing.
