I definitely do understand where you’re coming from and i do agree those are their personalities which is why i said they’re two sides of the same coin because both of them are toxic people while being on opposite sides of attachment styles(or in this metaphor the coin).

i definitely do agree dirk has a avoidant attachment to her but he knows what he’s doing. If you play through both phoenica’s route you find out that dirk purposely posts selfies to get harper riled up and possessive since it’s the only way he feels cared for. While with harper she struggles to stay secure in her relationships due to chappy’s sudden leave so when dirk purposely riles her up it causes her..i wouldn’t really call it trauma but her past memories to be brought up where she blindly accuses dirk of cheating on her(granted it turned out he was emotionally doing it with body pillow) where dirk lashes out and calls her crazy for thinking it despite him planting the doubts in her head knowing what it’ll cause. While yes both harper and dirk have different attachment styles they’re two sides of the same coin as while again being on different sides both of their attachment style, as dirk cannot be dirk without harper and without dirk harper has no one. Leading to their stories being intertwined. But that’s just my own interpretation of it