The Valentinians categorized humans into 3 distinct groups: the spiritual, psychical, and material.
Hippolytus wrote that the Valentinians split into two distinct groups, the Western (Italian), and the Eastern. The primary difference between the two groups, aside from geography, was that the Eastern Valentinians believed Jesus Christ’s body was spiritual, and that he was born from Mary as through a pipe, never making contact with her; the Western Valentinians held (what I consider to be) the original Christian belief, which posited that the Christ entered Jesus’ (psychic) body at the time of baptism.
In both cases, Jesus Christ’s flesh was distinct from typical human flesh.
The intriguing detail about this geographic divergence is that it seems to me the Eastern (as opposed to Western) Valentinians should have held the more adoptionist, Marcan position, which made a clear distinction between the Christ and the man.
The reason this divergence seem so strange to me is because Eastern Valentinianism strikes me as the earlier version; this a self-evident speculation, as most of the earliest Christianity sprung up in the Eastern part of the empire, between Roman Asia and Alexandria. Therefore, the Western Valentinians would seem the more likely candidates to have been influenced by late-iteration theologies, especially if one believes Irenaeus’ claims that many heretics went to Rome in the mid-2nd century.
With their adoptionist view, the Western Valentinians held a position similar to Marcion, in that Jesus Christ did not possess the same sort of flesh as normal humans do. The Acts of John expresses a similar sentiment as Marcionism in that Jesus did not even leave footprints as he walked.
The most economical speculation I can make about why the Eastern and Western Valentinians seem like they should hold the other’s position is because members of a still-evolving Eastern Valentinian sect moved west to Rome beginning sometime (perhaps) between 120 and 135, and more rigidly adhered to their original Eastern position, despite Western influence; likewise, the still-evolving Eastern Valentinians, more open to other philosophical points of view, integrated stories from other cultures, such as the Greek story of Perseus, whose mother was inseminated by Zeus who snuck through her underground chamber. Implied in this speculation is that the Eastern Valentinians (along with their philosophy) were never isolated; the fact that they were so integrated into the emerging Orthodoxy indicates that they were quite social, and therefore, probably also moving Westward, despite their name.
Alternatively, the Valentinian categorization of Westerners was simply a misnomer, and this divergence between the Valentinians was more-or-less parallel to the evolution of overarching Christian thought.
Taking one step further out onto the limb, one speculation is that an increasing number of sect leaders who claimed to be the Paraclete, or inheritors of Jesus’ spirit (the Christ), were diluting legitimacy for other high-ranking Paraclete-claimants. This detail, coupled with a clear progression away from mystical communication with Jesus and the divine realm in the beginning-to-mid-2nd century would explain the need to put Jesus’ birth as a centerpiece in the story: if Jesus was born inherently divine, then making claim to the body-hopping Christ, or any mystical communication in which Jesus revealed to you new directives, becomes more difficult. Therefore the existing power hierarchy within the church would be more difficult to supplant.
In this speculation, the alteration to the “Orthodox” position was that Jesus Christ transferred part of that spirit to his apostles, rather than some random passer-by, such as Simon of Cyrene or the Apostle Paul. This alteration would explain the emerging 2nd century anti-apostolic sentiment among Marcionites, a phenomenon that makes no sense at all in other circumstances…why on Earth would anyone ever be against Jesus’ hand-picked apostles? This historical detail is absurd when one relies on the traditional Christian narrative, but it becomes quite obvious when one factors in the paradigm shift the virgin birth allowed.