The more I think about this the more I think St. Louis made out like bandits here. And the general reaction on twitter seems to be the opposite. But Berglund and Sobotka are aging, 30-year old 3rd liners. They give Buffalo some decent depth, but you could have signed comparable players as free agents today. Then you got some picks that will be in the bottom 3rd of their rounds. And Tage Thompson who IIRC was a pretty questionable 1st rounder in his year.
All for one of the best two-way centres in the league. Buffalo was one of the few teams in the Atlantic or even in the league with him and Eichel to be able to match-up against Matthews/Tavares, and they threw that all away. Classic quantity for quality trade.