All that is to say ... Do what you want in who you choose to associate with, and it's ok to not let some people get too close. But try to avoid doing so in a judgemental, stigmatizing, labelling, or aggressive way. Keep these things lightly and open room for the idea that it's more of a simple misunderstanding rather than existential conflict. And don't stress about it too much.

I never know for sure whether someone suffers from narcissistic personality disorder or other dark triad traits so I rarely label them; but I can gauge the effect of their actions on me and that's the ultimate metric that matters. Even people with good intentions may produce hurtful and counterproductive actions and be unwilling or unable to learn and grow; there's no need to label or stigmatize them but I will, as you say, choose who I associate with to better my own life. It's helpful to remember that other adults are not owed time and attention; they are responsible for finding their own support networks to meet their needs in a mutually agreeable way. Obviously in a workplace no-contact isn't possible entirely but greyrocking works there.

It's just helpful to recognize the narcissistic traits and manipulative tactics that people sometimes use and respond appropriately to the tactics by enforcing boundaries, communicating my limits, refusing to get emotionally entangled, etc. Pretty much what standard therapy teaches.