Greetings in that Divine and Most Precious Name of Our Lord and Savior Jesus Christ!
The Church fathers were not creating a manipulative concept of the Virgin to persuade goddess worshipers to convert, the Fathers built our understanding of the Virgin based on fact and on our experience with Her directly. The idea that the Church invented or at least aligned its teachings to convert pagans is a blatantly divisive Protestant myth introduced to make the Church look bad. It is a bias approach to interpret the fact that the world shares so many of the same fundamental religious stories and concepts, and one which has the underlying assumption then that the Church's concepts of the Virgin are false as the goddesses.
We must be very specific to separate the concepts of pre-Christian mother goddesses and of the Mother of God in the Church. They are not the same in either form or function. The Mother of God, not just as a theological construct, but as a socio-cultural construct is quite different than were the Goddesses of the Mystery cults of olde. Mary is a human being, elevated to be a vessel for the Godhead, becoming a true bridge between the purely physical/human towards the purely spiritual/Divine. Human beings honor, revere, venerate, celebrate, mystify, and even mistakenly worship Her precisely because of Her humanity. Whereas, the goddesses of were part of a pantheon but still maintained some divine essence purely their own.
While it is complicated and a bit confusing to identify the functioning difference, it remains soundly in tact even in the most mistaken Mariolatry. Mary is not the source of the divine blessings, healing, or power which people seek from Her intercession, rather such comes from the Godhead. Perhaps Mary's mediation and our relationship with Her plays some role, but in the end, God can't be avoided. With the Mystery Cults, one learned and participated in the liturgies and incantations of these goddesses precisely to possess some spiritual fortitude from these goddesses alone, and not necessarily in connection with any other divinities of the pantheon. The goddesses were not bridges to the Divine, they were divine themselves.
The Church did not purposefully dupe goddess worshippers by giving them Mariology as a coy substitute, as anyone whoever worshipped a goddess might see the onstentatious glibness of it. No, Mariology exists on its terms as does goddess worship. Personally, I ascribe to a Joseph Campbell perspective, that there are certain mono-mythic constructs which permeate the human experience because they originate from a single well-spring and source. The Creation, the Flood, the Messiahs, the Mothers of God, the Death and Resurrection, the Eternal Life, these are part o the human mono-myth precisely because from our Christian perspective we believe them to be quite true and accurate. Joseph Campbell, without necessarily affirming one as more valid than the other, concludes that according to cultural anthropology these concepts must have a common origin, we in the Church just say the common origin is in our versions of the meta-narrative. Just as the Prophets envisioned the Christ, so did the other religions of the world share from the same vision. Christ came to fulfill any of these aspirations across the world, which is why all of us can universally relate to Him, why is the Savior of the World, and not just say of the Jews.
The world used to be permeated with Mother goddesses in blissful anticipation of that one true Mother of God who would come from that single family, and ever since then we have the true story to tell of the real and true Mother of God, Our Lady the Virgin Mary.