Interesting topic you come out with.
In my personal case, I don’t know. I have doubts about each one of my significant relations but I don’t think they are narcissist at all. The problem lay on myself. How I see myself. So, it’s up to a point normal that whoever is with me they are gonna be for the wrong reasons.
Another thing to consider is that depending on others, looking for support because you see yourself faulty is not very right either. It’s not fair with the other person because you don’t know up to what point you are being genuine or you are trying to fill in a hole, a lack.
It’s complicate and I resist myself to go here and there feeling a victim. I think everyone can be toxic for another person. It’s not needed they have a personality disorder.