Answer

1. As I understand it, his intention is to say that the soul is an entity, not a faculty. The various faculties are faculties of that one entity. I once wrote something similar regarding a discussion among psychologists. I once saw an article in Badad by a psychologist named Aharon-something, who examined what the “self” is on the psychoanalytic map of the human being, according to Nefesh HaChaim, the Tanya, and other thinkers. While reading it, I thought the whole article was built on a basic misunderstanding: the “self” is that which the psychoanalytic map describes, and therefore it will not be found within the map. It’s like asking: who is the person—the leg, the hand, the heart, or the fingers? All of these are organs of the person.
2. A possible practical implication is in the question whether the world is dualistic (matter-spirit) or monistic (matter), with spirit being merely a product of the material whole (emergence). If one understands that all these souls are not attributes and faculties of a single entity, but rather that there are several souls, then one can view them as different functions of the material whole. But I’m not sure about that.