intps are occasionally enneagram 3s in addition to the wider contingency of 5s, no? my take is that the 5s are very very stubborn and the 3s want to play social games that others find valuable, bc the sense of achievement within those games helps them feel shored up, valuable, purposeful, etc.
whereas 5s just want to feel like a supergenius, they are less behind-the-scenes and more "i need to be in-charge" like entjs. intps who are responsive and calm do work social situations far better, it is a much better and more natural use of their skills. when they want to be 8s bc they're 5s with a god-complex, their social ability starts breaking down.
even the 3s, tho, show very strong holes in "social charisma." they're just really fucking well-argued and well-defended, so you have to give them credit and recognize that they have their shit worked out most of the time. perhaps less than charisma they're just really fucking good at picking up the way the game is played and playing it well. they like all serious Ti folks love the challenge.
and that mostly they are more ok with doing something that fulfills the needs of a larger sphere rather than just focusing on their own, even if they are just as focused on/solely focused on their own success and self-perception (3w4 esp). but that can be better than e5 total self-absorption, depending on the approach and similarity of interests between the people. my best intp friend is a 5w4 and it gives us enough to talk about for years and years. the need for iconoclasm is like the foundation.