I coach a 13 year old who was clocked at the end of his middle school season throwing 79mph twice. He was throwing 77 consistently. He is playing travel ball this summer. He is 6'2 and 180lbs. He is a young 13 year old. I was wondering where he is at with other 13 year old kids. I also worry about how hard he is throwing already. He is monitored very well and his arm is taken care of really well.
If he is monitored well and his arm is taken care of well, why are you worried? I assume that monitoring includes limited pitch counts and limited innings over time.
As for your comparison question... as a 13 y.o., he throws hard, and as someone who is 6'2" 180 lbs, he does not. So, as RJM states, he needs to be focused on continued improvement because it won't be long before his size no longer provides a huge advantage. Others will close that gap. He'll need to extend it in other ways. Mechanics, movement, ability to locate, pitching know-how, fielding his position, holding runners, mental strength, conditioning, etc.