Something else I wanted to mention is that even though the risk of attachment disorder is apparently (anecdotally--not sure there is actually research) less likely the younger the baby, there is always the possibility. Situations surrounding birth, number of early caregivers, if the baby stays in the hospital vs going to a foster home--all of these can and will affect them even at just a few days old. One thing our SW told us is that all adopted children and babies have attachment issues--issues related to their adoption--that you have to help them work through. The difference is in how they present and how severe they are.
In the case of my middle child, they were pretty short lived and he adjusted very smoothy. In the case of my youngest, it affected him much more, and we are still dealing with its aftereffects. I suspect he will carry some into adulthood (trust of other people especially). Both had similar experiences in excellent foster care, although the youngest came home at 1y and the middle at 5.5m.
When they have trauma issues, sometimes you deal with them in ways that look, at first, to be very un-AP. For example, with my youngest who is now is preschool...He loves his school, his teacher, playing with his friends. He is not ready to go home when we pick him up. BUT he often still cries like you will never come back when he is dropped of. (we had a period of no tears, but now they are back recently, as Mama is hurt and unable to be herself and his world is topsy turvy again with Daddy and friends doing the drop off). My AP self would, and did with the other 2, stay and comfort and transition them to someone else's care, providng reassurance that they would trust and find solace in and they would go willingly with my promise of return. I tried that with him, because that is just what you do, never leave them crying, right? But Isaac...he will cry and scream like he is being physically injured. The longer you stay, the longer the tears, the more hysterical, and the longer it will take him to calm down. But if I leave, he is fine within 5 seconds (I have hid around the corner and counted). For him, drop off itself is not the problem, it is the sensation that he remembers of being handed off yet again. To him, is is subconscious reminder of a painful moment of leaving each caregiver that came before me, much how we may associate a scent of cologne with a long departed grandfather and get misty eyed. Because he was so young, it is a "sense memory" based on the physical sensations of leaving someone's arms and going to another person. The longer I stay, the greater the sense of anticipation of that moment that he knows is coming. He will then begin to cling and grasp and be so fearful. For him, it is more AP to hand off quickly, with a reassurance that I will be back that afternoon, a quick kiss, and a quick departure. Me not making it a big deal and being matter of fact, followed by reassurances throughout the day that I will be coming back this afternoon when he asks his teacher, is what he needs to feel secure.
). She checked that, of course, but also heard a couple stories that indirectly showed that we cosleep in various combinations and didn't press the question further.
I guess she shoved him out or something 
It's getting better as he gets older, but honestly, raising kids -- any kid from any womb -- is a crapshoot! 
I think I misunderstood your first post. For the most part, I agree with your second post. I'd guess that almost all of the time, that's true.
And dealing with true attachment disorders is extremely foreign and seemingly illogical and counterproductive to most people... even moreso to the AP community. I feel for people who have to deal with the disorder and then battle the rest of the world to attempt to explain or defend what they're doing.
I would guess that even kids with severe RAD will feel love and security fleetingly here and there, but for the most part you're trying to raise them to understand the rules of society, which are harder for people to follow when they don't have loving bonds in the world.
