The single point I want to mention in this post is that Christ did not assume human nature in general, but rather a specific human nature.
The Word of God "did not assume human nature in general, but 'in atomo'"--that is, in an individual--as Damascene says (De Fide Orth. iii, 11) otherwise every man would be the Word of God, even as Christ was (ST III Q2 A2 ad 3).
Now some might object that this means the Word assumed a person, because being a person is part of human nature. But St. Thomas says otherwise.
Yet we must bear in mind that not every individual in the genus of substance, even in rational nature, is a person, but that alone which exists by itself, and not that which exists in some more perfect thing. Hence the hand of Socrates, although it is a kind of individual, is not a person, because it does not exist by itself, but in something more perfect, viz. in the whole. And hence, too, this is signified by a "person" being defined as "an individual substance," for the hand is not a complete substance, but part of a substance. Therefore, although this human nature is a kind of individual in the genus of substance, it has not its own personality, because it does not exist separately, but in something more perfect, viz. in the Person of the Word.
This is consistent with Chalcedonian theology: "the union of the two natures took place in the Person."