At that age, he still has a lot to learn about the game. Scenarios, plays, defensive strategies, etc. Do you think he will learn at the same rate watching from the bench as he would being a part of the action during each game? I know a couple kids your son's age who might do ok with that task, but the vast majority would not. My 2018 LHP son learned so much about baseball between 7th and 9th grade that I can't imagine him taking this route. I guess I would just be thinking about his overall game development and knowledge and weighing that heavily before I made that type of decision. In my mind, the best way to learn is to play.