I would agree that the world of Myth is not a viable or coherent platform to use in a search for the truth; however, the other two aspects go hand in hand.
"Science" encompasses both natural and spiritual.
Natural science deals with known truth and unknown truth.
Spiritual science deals with known truth and unknown truth.
If you want to consider "myth" to be "spiritual", then it can be included to begin with, but every "myth" is false. Hence, the meaning in the dictionary for myth as "an unfounded or false notion". Anything spiritual that is a "known false" drops out of spiritual science. Adam is not a "known false". The inability to prove any science as true does not imply that the science is false. This is pretty basic. Agreed ?
Yes, there is such a thing as spiritual science, but it is commonly called Apologetics. No, this is not apologizing as the English language no uses the word.
Separation for "pragmatic" reasons ? Pragmatism is the fancy word for "quit" when one cannot deal with all of life as one whole realm. If one concludes that it is a pipe dream (quits) to view both with the same lens, it would seem to do discredit to both as they hold answers and proofs one for another. While this unification may represent something that only God can truly provide. He can and does provide it to those who seek Him and ask.
While you may not yet have been provided with an explanation of how the spiritual lives of Adam and Eve do indeed match the requirements of natural science, this does not mean that such an explanation does not exist. If you have been provided with such an explanation and have rejected it as unacceptable for personal reasons, re-iteration may not be of help.
Indeed, this explanation can be achieved for those who remain objective in their search for truth, however, such an exposition requires far more than a glancing post as it is built upon a foundation.
Adam's life is explainable in terms of science. The life of Adam is still part of truth in the science realm, and therefore it is much more prudent to prove Adam as a "myth" if you want to drop him out of science.
Life is much more meaningful since Adam is a figure that can be studied by science.
Natural science has not proven that Adam is a myth and this observation only leads to a rational path that does no harm to the meaning of myth since a myth is a "known false" and Adam is not a "known false".
If one insists that the life of Adam has been scientifically proven false, one is outside of truth already.
You may certainly legitimately consider "religion" separate from science.
The meaning of pure religion is found in James 1:27
Science deal with relationships and the meaning of a relationship with God is found in the volume of the Book.