From what I know, one doesn’t have to be such a baki in Tanach, just an extra measure of common sense. And knowing Mefarshim, Rishonim etc.won’t help a bit, they’re at a different “angle”, they’re not exactly “gores” the Rambam, Rishonim, Chazal etc.
You have to know the best way to size up your fellow and “explain” it to him / her, that carefully or randomly skewed “verses” don’t in and way shape or form refer to that individual. Any normal, sensible, unbiased court of law would trash out all “proofs”…
And then discuss the nature of his birth… (actually those “verses” have now been discontinued.. even they realize how utterly foolish it is..)