They are not as nicely nor as neatly packaged out, one to a body, as our psychologists believe. They constantly change. They grow. They make decisions. They use the physical body fully, or they partially depart according to their own inner needs and development.
When psychic gestalts are formed they are not static. They make different alliances until they find their place in a whole identity that severs their purposes, or are song enough to become indestructible. They are always becoming. they are not closed units.