I'm very interested in the role of the inferior function, especially with regard to how two people with opposite inferiors (Fe and Ti, Fi and Te) interact. For example, if you put an ENTJ and an INFP in a room together, how will each react to seeing his own main weakness reflected as the other's main strength? In my own experience, there is immediate mutual fascination and admiration. As an INFP, I look at an ENTJ and see the decisive, straightforward, go-getter attitude I see in myself only in brief glimpses, when I'm frustrated and my Te takes center stage. I can't really say what it's like for the ENTJ to see such concentrated Fi idealism.
What do the Fi-dom and Te-dom have to learn from each other? How would you describe the dynamic of the two types?