Where he falters, here, as I see it, is that while he accepts the overall Biblical/theological argument against the rejection/disabling of natural fertility, he can't quite see how this could apply to "every" act of sexual union.
Bu that's the standard that applies to all other moral choices: they are judged on an "each act" and not an "overall" basis.
I would not bank with a financial institution that said they can't vouch for every transaction being free of intentional fraud, only that their "overall" approach was "in general, honest."
I would not go to a doctor who said that he does not renounce the killing of patients precisely every time, though he is against killing "as a general rule."
I would not support a judge who said he would abide by the Constitution as written "for the most part," but he doesn't feel obliged to follow the Constitution in "each and every case."
I would say that the connection of normal, natural sexual intercourse with the normal, natural pattern of fertility is part of God's design, our "Constitution." And (to borrow a familiar phrase) what God has joined together --- sex and fertility ---- no man should put asunder.
But I do give him CREDIT because he knows the Holy Bible.
And what about those married who cannot have children or who are beyond childbearing?
I'm curious, how does Catholic-approved NFP (natural family planning) fit into that over-all standard of yours?