how capable is your friend? Starting him off too low is a waste of time. Find a bow that he can handle "comfortably". there is no need in dropping down to such low weight that it is anemic if he can easily handle more. Contrary to popular belief, bows of too light of draw weight can cause improper form issues too.
Develope all the proper form that you can, shoot tens of thousands of arrows, develope perfect muscle memmory. Now after all of that prep, make an error in form 3 times and it becomes a habbit.
BigJim