The Church teaches that there exist a necessity of a first man and first woman who was ensouled by God. That is conceded. The Church does not teach that the story of creation in Genesis is literal history and things happened as portrayed. You keep playing fast and easy by avoiding coming straight out and making a definitive statement about the historical, literal existence of the pair as portrayed in Genesis. Original sin is a mystery that we will never comprehend, much like the incarnation, the resurrection or the True Presence. Is it possible for the ancients to portray that mystery is such a simple narrative?
BTW, common sense ain’t always so common.