Allvin doesn't exactly have the best record as Director of European Scouting, if you look at how many of his guys have panned out, I hope him being Dir. Of Amateur scouting goes better for him.
I am still waiting for that "steal" of a pick out of him. I think Simon might be one of those as he was an older aged player that was drafted not so long ago while he was still Dir. of Euro scouting, but I hope for more home runs from him in the future.
Olund could be one, Bjorkqvist potentially...not even sure if he was in on those but likely. Same for Tiffels.
Allvin was hired as a scout in '06, then promoted to Head European Scout in '12. In that time, they drafted the following out of European Leagues (Europeans playing the North America would not have been his area of responsibility):
Alexander Pechurskiy (2008, Round 5)
Viktor Ekbom (2009, Round 6)
Tom Kuhnhackl (2010, Round 4)
Oskar Sundqvist (2012, Round 3) * From here on, as Director of European Scouting
Kasperi Kapanen (2014, Round 1)
Dominik Simon (2015, Round 5)
Filip Gustavsson (2016, Round 2)
Kasper Bjorkqvist (2016, Round 2)
Niclas Almari (2016, Round 5)
Jan Drozg (2017, Round 5)
Linus Olund (2017, Round 5)
Antti Alojarvi (2017, Round 6)
If we leave off the last two years as simply being too soon to judge, there's really only two outright busts during his tenure: Pechurskiy and Ekbom, both of which were made before he was in charge of European Scouting. Sundqvist may wash out in the end, but he's at least seen a decent number of NHL games, Kuhnhackl has to be considered a success for a fourth round pick, and Kapanen, Simon and Gustavsson are all headed in the right direction.
Realistically, "steals" are more a product of luck, than of skill of the scouts, these days. It's not like in the old days when the Red Wings were the only team doing much scouting of Europe.