I’ve taken two dogs at nine weeks. Both are sweet, but both have problems, having been in less than optimal environments. I think that in many, if not most cases, 9 weeks is a good time to bring in a new puppy.
We adopted a gorgeous little Sheltie at eight weeks. He was uber-healthy, but he plunged into a deep pit of depression after we brought him home. He refused to eat or even get up and walk around for three days. Finally he snapped out of it, and became the best dog we ever had. At the time I just thought he was unusually attached to his mother and siblings. Later, when I read that most dog experts recommend nine weeks, and I read their reasons, it all fell into place. I’ve advocated nine weeks ever since, but as you illustrated, there are plenty of exceptions.