As someone who grew up in a technically poor (meaning it didn't feel that way since they hid it well for us) with a comparable number of siblings (won't say exactly how many as to avoid fingerprinting), I know it can be done without military dicipline, because we had nothing of that.

How they did it is more of a mystery even if I saw it first hand. And today I feel I really struggle to let my children experience the fantastic childhood I had, even though I have less than half as many kids as my parents had - and a way better job.