If the scouts are praising Tuomaala to go high in the first round i believe that it is for a reason too.
Do these scouts you are talking about have a proven track record and some credibility in the business? Have these scouts you are talking about travelled around North America and Europe to see all the notable 2021 eligible prospects? How many times have these scouts seen Tuomaala play live?
There are plenty of self-appointed scouts out there with a twitter account and a blog page, but only a few of them are worth following and they don't pretend to bigger than they really are.
As far as so-called scouting agencies go, most of their staff comprises of prospect nerds just like us that do some scouting as a hobby. Some of these hobbyists are gifted at what they do and eventually move on to work for NHL/CHL/USHL teams, but that by no means is a guarantee of overall quality, especially when looking at rankings published two years before the draft.
Some examples from ISS top-30 for 2013 NHL draft that was published with their 2011 Draft Guide:
4. Alex Forsberg (didn't get drafted and played university hockey last season)
6. Victor Crus Rydberg (5th round pick that now plays 3rd tier hockey in Sweden)
7. Hudson Fasching (4th round pick that developed into a decent AHL player)
8. Keegan Kanzig (3rd round pick that played in ECHL last season)
10. Nicholas Baptiste (3rd round pick that developed into a tweener)
13. Jared Hauf (didn't get drafted and played university hockey last season)
16. Jordan Maletta (didn't get drafted, coached in juniors last season)
19. Spenser Jensen (didn't get drafted and played university hockey last season)
21. Taylor Cammarata (3rd round pick and played in ECHL last season)
23. Kyle Burroughs (7th round pick that developed into a decent AHL player)
Forum rules prohibits me from posting the whole ranking, but I can tell you that Jonathan Drouin, Elias Lindholm, Bo Horvat, Max Domi, Josh Morrissey, Alexander Wennberg, Nikita Zadorov, Anthony Mantha and Andre Burakovsky are some of the notable names missing from that list.
Mckeen's Hockey released a top-12 ranking for 2014 draft with their 2012 draft guide. Their top-6 looks surprisingly good, but but after that the ranking goes down hill quite fast:
7. Joshua Jacobs (2nd round pick)
8. Eric Cornel (2nd round pick)
9. Brandon Robinson (didn't get drafted)
10. Reid Duke (6th round pick)
11. Jakub Vrana (1st round pick, 13th overall)
12. Daniel Audette (5th round pick)
Future Considerations released a top-10 ranking for 2014 with their 2012 draft guide:
1. Aaron Ekblad (selected 1st overall)
2. Sam Reinhart (2nd overall)
3. Nick Ritchie (10th overall)
4. Ivan Barbashev (2nd round pick)
5. Blake Clarke (didn't get drafted)
6. Roland McKeown (2nd round pick)
7. Jake Virtanen (6th overall)
8. Joshua Ho-Sang (28th overall)
9. Tony DeAngelo (19th overall)
10. Keegan Iverson (3rd round pick)
This doesn't look that bad but there are still some obvious misses like Clarke, Iverson and perhaps McKeown as well. And not having Leon Draisaitl there is a major omission of course.
As a summary: Using some source criticism might not be a bad idea.