If you're referring to McGrady and Yao, I don't agree. Star potential was easy to spot in them even as rookies. McGrady had a 17.4 PER as an 18 year old and a 20.6 PER as a 19 year old. Yao had a 20.6 PER in his first year, jumping from the CBA to NBA.
He's just saying that to satisfy the Morey-worship camp, to show them he pulled some genius moves by trading average players in and out.
Not sure these qualify but there have been numerous players who struggled and reached stardom with other teams. Billups Petrovic Dale Ellis Just to name 3 off the top of my head, some guys just take a while and with the NBA now having some really young players enter the league, maybe they are still developing? Just my .02 DD