Originally Posted by Tzu men

Um basically, name Sarutobi in Naruto comes from the legendary ninja Sarutobi Sasuke. Sarutobi means, "monkey-jump," and he was renowned for having amazing agility - like a monkey. Because Enma had a Konoha headband and due to the relation to his name, it is very likely that only the Sarutobi clan can summon apes. Judging by Orochimaru's anger at seeing Enma it is possible that they are the very strongest of all summons. Maybe if we are lucky we'll get to see Konohamaru summon them, or see Asuma using them in a flash-back to prove whether this is true or not.