I'm just spitballing but if we put actual numbers to it I see what you are saying.
So an above average regular would be what, 2.5 WAR? What would a star be? I think he's probably like a 50% probability to be a 1.5 to 2 WAR player. He hits the ball hard and showed massive amounts of improvement from year 1 to year 2. I think he can improve even more.