Ultimately, we would approach a posited explanation the same way something like, say, the theory of relativity was approached. Let’s treat it as though it were true and look at what follows; the fruit proves out what you are calling the tree.
In my case I have discovered the bald statement “God is love” explains a whole lot. It orients the entire scripture and gives place to a lot of details. The “why” question also tells us how far we need to go in discussing the “what.” One of the biggest pitfalls we can get into when discussing such things is to discuss them for the sake of pride and not love. Big, angry, snotty wringle-wrangles like what appear in this thread result. I think we do not even NEED to answer the OEC/YEC dichotomy definitively to have a very robust Christian life. I lean OEC because of Romans 1:20 (OEC models give us a deeper display of God’s glory to be amazed at) but I don’t beat anyone over the head with it.
Any scientific theory is subject to being falsified by testing. Are you prepared to submit your metaphysics to testing, and admit that it's wrong if the evidence doesn't support it?