Writer is just saying some players can only shine in proper systems. See Boris Diaw, Danny Green for examples. I don't think the writer was comparing Lin's potential to Leonard's, but rather Leonard most likely won't be get as far as he did on any other team.
Lin's full potential is not that much lower than Parker in my honest opinion. Parker/Manu were extremely lucky coming into the Spurs team when our perimeter was at its weakest. Too many players buried on the bench because coach was too afraid to play them or too lazy to develop low picks. Lin always played well against Parker/Spurs (and players/teams that rely on brain/finesse than sheer athleticism), and after Lin dropped 38 points on the Spurs, Parker even compared Lin to his younger self.
http://probasketballtalk.nbcsports.c...g-tony-parker/
Harden ball hugging and lack of touches really hurt Lin's game. Beverley is ridiculously overrated as a defender. Lin is taller and a much better system defender. He had Liliard under control for the entire second half and his coach pulled him at the final second and ate a three.
Put Lin on the Spurs I guarantee he brings more to the table than Patty Mills. His at ude is as Spurs as it gets (did not take any major endorsements the year of Linsanity when he could have really cashed in). Add in his marketing value he is worth 4-5 million a year easily. He just needs a good coach to yell at him and actual touches/playing time. Spurs's international atmosphere and system fits him better than anyone. A steal to pick him up at 3-4 million a year from now when his current contract expires.