I have just a few points to share here. First, doing this to people who were child soldiers and now may be older but still traumatized is like victimizing them twice. Second, privatizing armies is exactly what Rome did and then what the Eastern Roman Empire, what erroneously call the Byzantine Empire, did. Where are they? Oh, they both fell and part of it was that their own citizens got so fat, dumb, and happy that they lost the feeling they needed to sometimes sacrifice for the good of the country. I pray we don't ever get to that point.
If you need an example of how societies can develop into solider-generating machines, look at the Arabs who call themselves 'Palestinians'. They teach their children from a young age to hate and die for their leaders, and they actually are awarded 'A's in school if they get arrested during final exams for throwing rocks or firebombs at people. The whole culture has been turned into a weapon, taking a deliberately disadvantaged society and shaping it for evil purposes. Daily attacks - attempted murder, car attacks, bombs, rocks and fires are caused by these young soldiers, trying to terrorize the Israeli's.
Another example would be the child soldiers of Kony's army, who are stolen from their parents, tortured and starved, until they swear alliegance and serve his purposes. It is far harder to kill a child than an adult, but when they are trying to kill you, the good guys have no real choice.