I wouldn't draw conclusions based on no direct evidence!
Prosser is more skilled than both of these guys. He's a far better offensive player than Fay.
Also, a straight comparison of their careers in Class A and the assumption it's a big leap doesn't hold water here. Putnam County plays in a weak conference, and Nashville is a small southern IL. school that plays teams with not much physical presence. Eureka is in the Corn Belt, a strong conference night in and night out that plays a very physical style.
More importantly, don't forget that Prosser was a standout on the AAU circuit against top players from all over the country and coveted by big-time D1 programs. Fay and O'Rear's top level of recruiting was the Valley.
JP is a capable big who will easily be the best post player BU has next year. He should start or at least get big minutes right out of the box.