I think by identifying these views {anhypostatic/enhypostatic} as heretical, I've answered your question.
Therein is your error. Your argument is with Christendom, not me.
When speaking of
Person the church always understands the word to mean that
a person is an independent entity, indivisible, rational, incommunicable, not sustained by another nature but possessing in itself the principle of its operation. The Second Person of the Trinity took up a human
nature, not a human
person implying possession of independent existence. When speaking of the Trinity and the Incarnation one of the problems in understanding the patristic use of
person is that we anachronistically import modern psychological concepts into the idea of
person—versus how the word was used by the church in denouncing heresies—in a way that would lead to one of the many possible errors you are now entertaining.
Tolle lege...
Donald Macleod,
The Person of Christ:
Christ took human nature, but he did not take a man. He took the form of a servant (Philippians 2:7), but not a servant. He did not even take an existing human genotype or embryo. He created the genotype in union with himself, and it’s ‘personality’ developed only in union with the Son of God . . . [H]e is a divine person who, without ‘adopting’ an existing human person took our human nature and entered upon the whole range of human experiences.
Heinrich Heppe,
Reformed Dogmatics:
The humanity taken up into the person of the Logos is, then, not a personal man but human nature without personal subsistence.
Fred Sanders,
Jesus in Trinitarian Perspective: An Introductory Christology:
On the one hand, the human nature of Jesus Christ is in fact a nature joined to a person, and therefore enhypostatic, or personalized. But the person who personalizes the human nature of Christ is not a created human person (like all the other persons personalizing the other human natures we encounter); rather it is the eternal second person of the Trinity. So the human nature of Christ is personal, but with a personhood from above.
Torrance, Thomas F.
The Christian Doctrine of God, One Being Three Persons:
Classical Christology, under the illuminating guidance of Cyril of Alexandria, explained this in relation to the twin concepts of anhypostatos and enhypostatos . This was further developed by Severus of Antioch and John of Damascus. By ‘anhypostatic’ it was asserted that in the assumption of the flesh the human nature of Christ had no independent hypostasis or subsistence apart from the event of the incarnation, apart from hypostatic union, which ruled out any adoptionist error. By ‘enhypostatic’, however, it was asserted that in the assumption of the flesh the human nature of Christ was given a real concrete hypostasis or subsistence within the hypostatic union—it was enhypostatic in the incarnate Son or Word of God—which ruled out any Apollinarian or monophysite error. The concepts of anhypostasis and enhypostasis are complementary and inseparable.
Elwell, Walter A.
Evangelical dictionary of theology: Second Edition:
Further controversies were yet to arise before the mind of the church could be made up as to how the human nature could indeed retain its complete humanity and yet be without independent subsistence. It was Leontius of Byzantium who advanced the formula that enabled the majority to agree on an interpretation of the Chalcedonian formula. The human nature of Christ, he taught, was not an independent hypostasis (anhypostatic), but it was enhypostatic, i.e., it had its subsistence in and through the Logos.
Bromiley, G. W., D. Orthodoxy, and D. M. Baillie. “Christology.” Ed. Geoffrey W. Bromiley.
The International Standard Bible Encyclopedia, Revised 1979–1988:
F. Eutychianism After the condemnation of Nestorius at Ephesus (431) the opposite extreme was again reached in Eutyches of Alexandria, who pressed the unity of Christ to the point of a unity of nature rather than of person, thus absorbing the human nature into the divine. In answer to this new Docetism, and to the whole problem of divine and human natures in one person, the Council of Chalcedon (451) finally achieved the balanced statement that in Christ two natures are united in one person or hypostasis, without confusion, conversion, division, or separation. In explanation of the possibility of true humanity without an independent hypostasis (anhypostatic), as Cyril of Alexandria has already urged against Nestorius, it was taught by Leontius of Byzantium that the human nature of Christ is enhypostatic, i.e., that it has its substance in and through the lógos.
Considered in itself and abstracted from its personalizing by the eternal person of the Son, the human nature of Jesus Christ is simply human nature, and is not personal. The human nature of Christ, therefore, is both
anhypostatic (not personal in itself) and
enhypostatic (personalized by union with the eternal person of the Son).
The humanity of Jesus had no existence apart from the incarnation of the Word (John 1:1,14). Again,
the human nature is indeed personal, but with a personhood from above. In short, in the Person of Our Lord there is one
who (person - Divine Logos) and two
whats (natures - divine and human).
AMR