I just linked you the list. You can't name them because they don't play there, because it's not common. Because it's not easy for an 18 year old. Hell, the #1 projected Jack Hughes is showing you right now why they don't usually play there. They rarely have anything to contribute.
You either believe that none of these should matter or that all of them should matter, you do not pick and choose.
Elite Prospects - WJC-20 Stats All-time season
Go look at this list. Look at these names. It's half gold and half garbage. An overrated competition. Same goes for U18 with Pulkkinen, Rajala etc at the top. Blah.
Juolevi got picked almost solely because of his u20 performance. That went well. Pulju ripped U20's and U18's apart. That went well.
Either you give all of these value or you do not give any of them value. There's no in-between. You're not a scout, you probably do not know any team scouts and thus I can say with 11110% certainty that you have no idea whether these affect anything or not. You do not have any data to support your claim.