Berglund - Schenn - Tarasenko
Sobotka - Stastny - Steen
Upshall - Brodziak - Jaskin
Paajarvi - Sundqvist -Barbashev
We desperately need to get Berglund on a scoring line. Let him battle down low with Schenn and open up areas for Tarasenko up high. Take Jaskin off good players' wings, he's more effective with muckers anyway. Pray Steen remembers how to shoot the puck at some point.
Jakin did well with Schwartz/Schenn combo and did well with Stastny. He struggles with Berglund, Backes and Brouwer. There were reams and reams of WOWY stats to back this up before my favorite WoWY sites went down.
Berglund scores on his own but makes linemates worse due to his holding the puck and not being able to create as well as others. Again, reams of WOWY dats supports this. Putting him with scorers would diminish the effectiveness of the scorers but not increase Berlgund's effectiveness to as great an extent.
Berglund's GF 60 5v5 WoWY 2016-17
With Tarasenko (65 minutes) - 0 GF/60
Without Tarasenko - 1.95
Tarasenko w/o Berglund - 2.84
Both players took a big hit as they were unable to score together in 4-6 games worth of ice time.
With Schwartz (189 minutes) - 1.27 GF/60
Without Schwartz - 1.95
Schwartz without Berglund - 3.13
While Berglund took a small hit playing with Schwartz, Schwartz production dropped like a rock playing with Berglund.
With Paajarvi (155 minutes) - 3.47
Without Paajarvi - 1.54
Paajarvi without Berglund - 2.7
Berglund's game was actually boosted more playing with Paajarvi than anyone else. Granted Berglund still killed Paajarvi's game, but that's just what Berglund does.
BTW, this year, Schenn and Schwartz scored at a 8.6 goals per 60 pace with Jaskin on their line 5v5. They scored at a 4.02 g/60 pace when together with anybody else. But sure, he does better with muckers.
History seems to contradict your eye test analysis. Look into whatever other data you want. This data is not an outlier for Berglund. Its a theme.