I think too it gives me a bit of pause that he's apparently not very well-versed in the literature/theoretical understanding of how this stuff works. There have been things that have come up in therapy that were pretty unexpected (to me, anyway) and my T said, "Oh, yeah, that actually makes perfect sense because of this relationship dynamic or this developmental thing..." And then I go and look it up and see that she's right and not just making stuff up. So it's not necessarily just being comfortable with attachment but it's also understanding how it works and why and being able to talk through it. I think particularly given that you didn't seem to have parents who knew how to give you what you needed, that aspect of growth could be really important for you if handled skillfully.