Duh: the former.
There are approximately 351 D-1 schools. That's somewhere on the order of 4563 scholarship players. It was reported here that there are roughly 420 or so NBA roster spots.
You may, but I don't think that 3650 of the 4563 (80%) have NBA dreams. I'll refine that by saying perhaps 80% would love to one day play in the league; however, I'm willing to opine that they don't overestimate their chances of doing so.
If, say, 75% of the top 100 D-1 rosters really think they have a shot at playing in the NBA, that's 975 kids. I don't have to keep doing the math to show that doesn't equal 3650.
Crean recruits in the same stratosphere as perhaps - perhaps - 30 other schools. Maybe 80% of the kids on those schools' radar think they'll leave school early for the League.