Main difference is that most of those players either have more speed or play a much stronger / physical game than Petan.
I think that Petan can be a good NHLer in the right circumstances, but I'm not sure that those circumstances will be there now that Connor and Roslovic look to be firmly ahead of him in the depth chart (and rightly so).
Now, the wing depth is... Wheeler, Ehlers, Laine, Perreault, Connor, Copp, Roslovic, Tanev, Dano... Petan/Lemieux. Even if you move Petan up a few slots, he isn't in the top 5-7 wingers.