Most of those grown men in the SEL can't do crap and are washed up. NHL is a completely different league compared to Nylander's league. The fact that every single aspect of the game changes, even the ice, means no easy transition for Nylander. I do however agree he will become a future NHL stud with the right development, but you can't just say that "oh nylander played in the SEL, he's definitely going to be ready to play in the NHL". NHL is way more fast paced, smaller ice, physicality, and sometimes that extra ruggedness that the SEL doesn't have.
I'll keep my Virtanen.