“They are empty inside. They have to look to outside sources to define them.” –is pretty much the definition of narcissism. When there’s no empathy/compassion for one’s self or others- people with this inner scarcity flee to external validation for the rush/high of social acceptance as a substitute for self acceptance. But because they are empty inside (lack compassion) they see others as being empty inside too, as being little more than objects to give them feelings of worth.
So you need to be more specific with what you’re asking, I guess is my point. Having poor boundaries and putting others’ needs ahead of one’s own (to one’s own detriment) does not mean someone is “empty inside”. The people who need to impose ‘group think’- who feel entitled to control what others’ opinions are (usually through manipulation, often without realizing they’re doing it), and who lack appropriate boundaries- are actually the ones who are “empty inside” and they need external validation to fill the hole.
Narcissists are actually drawn to people with weak boundaries precisely for this reason- it’s easier to convince them to give and give and give validation without actually returning it.
I’m really not sure how to answer which type has the most issues with identity/boundaries because each type has its own issues. But I think Fe doms are just as inclined to end up on the “needing to overstep boundaries and control others’ perception to fill emptiness inside” end of the spectrum as they are to end up on the side of ignoring their own needs to see to someone else’s. It’s a craps shoot.
eta: And does anyone else think it's funny that someone with a Gollum avi started this thread?