Look... No one knows who will be the best player of this draft. Players take different time in developing. Some are monsters right out of the gate - McDavid, Matthews, etc etc -, some take longer, sometimes much longer - like Hedman for example.
But this is a "very early redraft" thread. What has changed from draft day? Roughly 1 month of hockey was played in the 17-18 season all around the world. That's ALL that changed and that's all that can be taken into consideration.
And no matter what performance Pettersson or anyone else has done in Europe or in the Juniors, it. does. not. compare. to. playing. in. the. NHL.
Making an analogy, it's like trying to peddle that someone driving top level in F3 or go karts is currently better than someone driving at top level in F1. Not a chance.
PS: and about physique not being adequate for playing in the NHL re Pettersson... Have you seen Hischier? He almost looks malnourished...