I think that , obviously Red John is a much older guy as he has been killing for years, however, the writers of the show want to create an organisation so that after we know who Red John is the show still has a storyline to continue into another season. 

If there are several people working for Red John it makes sense to flush them out in almost every other episode. What would be interesting is to see how he actually indoctrinates them into doing whatever he wants and then killing themselves when caught. 

In short i think its Bret Stiles he has that power to convince, however i don't think he has the physical capability to do so , so his killings are performed by someone younger, he is just the man behind the curtain.