I helped teach a junior golf program for ten years and we always started with putting, then chipping, pitch shots, full swing with an iron, and then driving. It’s a logical progression, plus it’s the best way for most everyone to improve. I’ve done a fair amount of instruction and most people will find improvement in their scores by working on their game from the hole backwards. Juniors, especially teenage boys, typically want to focus on distance and aren’t realistic about improving their putting and short game.