Edited "fall" to "fail".

the second sentence means I am trying to distinguish between who someone is and who they might have been. Another intuition pump: put identical theists in identical rooms, on one play a television program explaining how they have to admit that all good evidence makes it unlikely there exists (insert theological thing here, an Adam and eve, a soul, whatever) and on the other play something unrelated to the issue. Then ask the previously identical people if they believe in whatever poorly backed theological thing they previously believed. the unorthodox will flee the false position, but only if they see it as obviously false.

Something like this.

Often, though on occasion their reasons are isomorphic to stories we'd find plausible.

That doesn't mean the reasons we find it implausible aren't good or can't be taught., just as teaching how carbon dating relates to the age of the Earth militates against believing it is ~6,000 years old, one can show why what ancestors tell you in dreams isn't good evidence.

So my conclusion, my supposition, is that if you muster up the most theistic-compatible metaphysics you find plausible, and show it to those theists who don't know why anything more supernatural is implausible, inconsistent or incoherent, they will reject it.

That they accept it after learning that you have good objections to anything more theistic is not impressive at all.