How about Damien Lilliard, who wasn't even ranked when he went to Weber State.
Tyrus Thomas wasn't ranked when he went to LSU, who wasn't a major power when he was there.
Ever heard of a guy named Paul George? He wasn't ranked either when he went to Fresno State. I bet he wishes they had done more to develop him into an NBA player...oh wait.
Lots of coaches outside the traditional powers are perfectly capable of developing players who aren't even ranked coming out of high school into NBA lottery talent.