They most certainly could, the fix is obvious, and it has been done before in history. I can’t personally recommend it, but there are societies that don’t believe in God. They might have a different calculus, and unfortunately Africa isn’t going to stop being an inviting target any time soon.

monasteries took intelligent people and certainly did not focus on eliminating low IQ people from the reproduction pool.

it is absurd to assert otherwise, the monasteries could NOT have preserved the knowledge of the Romans and Greeks without having the wit to manufacture scrolls and copy the works into new books and formats without many moderate to high functioning individuals.

monasteries tended to be the destination for surplus sons as the firstborn typically inherited whatever property might be in the estate and the younger sons had to make their way via military service or Church otherwise and craftspeople tended to be lower class yet than the military / clerical ranks.