Responses
The people there are poor and since the workshop is design for a dwarf, and children are a perfect fit at the workshop. Besides, you'll be surprised just how strong kids from the poor are, since I was one myself. And seeing as so many children are working, I'm guessing they change shift a lot. I doubt they even let the kids do the hammering tho.
When they said giving poor children work... Isn't that a mellow way of saying child labour ?? (〜 ̄△ ̄)〜