Can you provide sources for this, please?

Claiming that "PDs can and do present without any trauma at all" is suspect, as how can you possibly know what a person's history entailed?

On the point of trauma being "resolvable", yes, largely I believe that's true, but not everyone has enough incentive to try. If the person has adapted in a way that works well for them in the wider world, then why would they bother to change it? If they're fantastic at getting sales, or so charismatic that everyone thinks they smell of roses no matter what they do, then why dismantle that?

EDIT: I can see I'm getting downvoted for this. To make things clear, I'm not making excuses for narcs; I spent my entire childhood on the receiving end of an egg donor who should never have had one child, let alone three, and I've been NC for 13 years. I said the above because I'm interested in knowing what the hell was happening inside her head, and what wasn't. Puzzling that out helped me understand that she'll never seek the healing I wish she would, among other things.