Hoskins, Kingery and Pullin are dominating their respective leagues and are age appropriate. Can't ask them to do much more.
Cozens is more of a question mark, check back in August, but as far as raw talent, he's probably the top guy in the system.
Ortiz is the wildcard, he's in XST because he's only 18, but he has a man's body.
Moniak right now isn't all star material, he'd have to add 20 lbs, and develop plus power, and so far he's not showing exceptional contact, but he's 19 at Lakewood, things could turn quickly.
Pitchers - two kinds, those who come out of the sea on the half shell (Hamels, Nola) and need little development, and those who have to tame their talent.
Kilome, Medina, Pivetta et al have the stuff, but need years to refine it and become pitchers.
Eshelman, Fanti could move very quickly.
Sanchez might be the rare fireballer who can also pitch, and if so, he'll start jumping leagues by next year.
Problem is you usually don't know you have a star until they explode, like the big three this year at Lehigh and Reading - if they sustain close to 1.000 OPS for a full season, only ML service will tell you if they're for real, because you can't ask more from a young prospect than to completely dominate their level of play.