Would you agree that Serg has better offensive skills/potential but he is more a risk that Juolevi?
Juolevi is going to be a very solid NHL defenseman, as is Jacob Chychrun. They are both quiet, steady Jay Bouwmeester-type players who should be very dependable.
Sergachev is the only one out of the three that offers "dynamic", which is to say "highlight-reel" ability. His shot is a bomb, he hits like a truck, he is willing to take more risks with the puck. Does that make HIM a risk as a draft pick? I would say no. I would say, however, he is the least polished defensively out of the three and likely furthest from the NHL due to this.
Oh, I agree with you on Reinhart too, by the way. I'm shooting you a link to the article I wrote the night of the trade. My words were not scathing, as I find it morally abhorrent to write that a 20 year old kid is a "bust", but I kind of alluded to it when I mentioned his "upside as a steady, mid-pairing defenseman". When the Isles drafted him I had the same reaction as when Columbus drafted Murray -- that neither had an upside even in Jacob Trouba's league.
In 2012, 8 D were taken in the top 10: Murray, Reinhart, Reilly, Dumba, Lindholm, Pouliot, Trouba and Koekkoek. That year, I said repeatedly Trouba was the best out of the 8. I also liked Reilly and Dumba a lot. I was wrong that I thought Anaheim's selection of Lindholm was awful, but I was right that I thought Murray and Reinhart were both middling prospects, not top 5 picks. As a group I would rank them below the 2016 top 8 D, who I will rank here, for you.
http://www.todaysslapshot.com/edmonton-oilers/oilers-erred-by-trading-for-griffin-reinhart/
1 Sergachev
2 Chychrun
3 Juolevi
4 Fabbro
5 McAvoy
6 Fox
7 Bean
8 Peeke
(I have Dineen as my #9)