Schools rarely extend offers to players if they haven't done a thorough evaluation. The assigning of stars between a 2 star and 3 star is unscientific and subjective. A 2 star with multiple offers is likely better than a 3 star with one offer. Regardless, it is probably fairly clear to coaches after about 2 or 3 days of fall practice how good a player is (I doubt they ever talk about "star ratings" at that point).