Kabbalah – United souls create a unified consciousness? Conception and reincarnation and understanding the parts of the NRN

In the SD
Hello Rabbi!
I wanted to ask the Rabbi Shlita (and perhaps the late Rabbi Shlita, according to the Ship of Theseus in Changes of Opinion, etc.), a question. I understood that according to Kabbalah (or at least according to certain methods), there are concepts such as reincarnation and transmigration:
And let's assume that the person who feels and experiences in the simple levels is described by the term soul, and this is the fundamental element of the living being. But on top of this description, we add that it is possible for there to be several souls or sparks that will incarnate in a kind of compound in a single person. Or as we put it, the term soul fertilization, that a soul that is not part of the original person will incarnate in him during his life or for certain moments. (Although there is some room for disagreement because soul is a high level and therefore it is ostensibly something trivial for a person).
And now, I know the Rabbi's interpretation of the Baal Tanya method with the studies that investigate in the Mishnah of the Baal Tanya where exactly "man" is placed according to his method. So for example, the divine soul and the animal soul are parts of the same "man" and compose him. Therefore, the search between the entity and what composes it creates confusion for some. Because the compositions are part of the entity. And not according to Leibniz's principle of the identity of the indistinguishable.
But I wanted to ask, if we assume that several souls reincarnate into one person, how could this explain the unity of consciousness . Which is one of the most important and powerful evidences of philosophers for dualism and the acceptance of the soul as a relatively "unitary" thing. (Or at least not composed of many people…).
And here I do think that the question arises as to who that "person" is, and the Rabbi's excuse in Baal Tanya will not be helpful in this regard. And here it sounds really, really unlikely.
And along the way, I would be happy if the rabbi could bring to mind (or point to) a place that explains the relationships between the parts of the NRN, and in particular how each part of a language is composed of or can be combined with parts of other "people." Because simply when I heard these things, they seemed very puzzling to me, and even when I discussed them with people who are supposed to understand, they seemed to "accept" these things and less to try to bring them to mind.
 
PS
The relationship between different souls and compounds of the unity of consciousness appears on the one hand as an emergent principle brought forth by the materialists, but it does seem to have a drawback because each soul must be understood as something that feels in the present, and not feels in a connected way.