… we found reason to conclude that “formed from dust” was archetypal rather than a description pertaining to Adam alone. We have also seen reason to believe that “rib” should be understood as “side.” Furthermore, we have suggested that Adam has seen Eve’s formation in a vison but that the vision conveys an ontological truth with Eve serving as an archetype. In both cases, the archetypal interpretation offers the reader significant theology about the identity of mankind and womankind. As such, it does not, however, make definitive claims about the identity of mankind and womankind. If Genesis 2 makes no claims about material human origins, one would find no other statement in the Bible to offer details beyond the fact that we are all God’s creatures. [John H. Walton, The Lost World of Adam and Eve: Genesis 2-3 and the Human Origins Debate (Downers Grove, IL: IVP, 2015), 81]
As opposed to federal headship, Walton believes that Adam and Eve are archetypal humans, and that Genesis 2 does not offer a real historical narrative of Adam and Eve as the first human couple. Now, an archetype does exist as a real person(s), but that is different from saying Adam and Eve exist as how the Bible describes Adam and Eve as the first human couple created de novo.
Obviously, if one were to follow Walton's interpretation of Genesis 2, then we can say goodbye to Adam's federal headship and Reformed covenant theology.