I don’t know if the ratio of our relatively small community is 1:1 (it sure isn’t in my house). Nor do I think that a crisis is born from one generation to the next. I doubt the growth is that much. But, as Popa said, your math is wrong. The quoted idea is as follows.
If there are five boys and five girls in generation 1, and the girls all marry boys from generation 0 while the boys marry five girls from generation 2, this would leave over another five in a situation where the population doubles in a generation. The ten boys in generation 2 will marry ten out 20 girls from generation 3. This will leave over 10 girls from gen3 in addition to the five from gen2.