I fully support you in this.
1. The Boys could not have been sent to Prison because of their age - you only go to Prison as an adult : ie 18 years old or older.
2. Conscription only applied to Adults - 18 years old or older.
3. They could not be made to enlist as enlistment is entirely voluntary.
Of course, it may be that some were coerced by people whose duty it was to care for them - but if that could be proved then I would suspect that the level of damages awarded in Court of Law against those people would make a few eyes water.