Virtanen with the Sedins was stupid.
Virtanen does not have the brain power to work with 2 of the most cerebral players to ever play the game.
If you think Pettersson & Dahlen are cerebral then you would be wrong.
There is no Sedinery with these players...they complement each other and that's it.
With the style of Pettersson & Dahlen...they could definitely use a power winger like Virtanen.
Virtanen's forechecking ability and physicality has usefulness on any line, and is preferable to the wingers that the Sedins would have otherwise played with, or the Sutter/Gagner types that Pettersson would otherwise play with. But it would not be anything close to an ideal fit, IMO.
Pettersson is absolutely a cerebral player-- his primary game involves controlling the puck, playing give and go and diligently finding holes to exploit and attack in the defense. He's a very east west player, whom Virtanen has not shown the hockey IQ, playmaking instincts, ability to get open/one-time the puck, or even net presence to optimize Pettersson's game-- Some areas in his game (he still has some tunnel-vision) would flat out end up being a boat anchor for his offense, IMO. It's like playing early career Hansen, Bernier, or David Booth with Naslund. It wouldn't be entirely useless, but doesn't totally work either (not as well as guys who can think the game a compatible way but contribute similarly like Pyatt, Higgins, or Cooke, anyways).
Virtanen is better utilized helping out players like Horvat, Gaudette, Sutter, and Gaunce (who actually complement his game offensively and bring the most out of him) than guys like Pettersson, IMO.
Virtanen is not a player who is helped all that much by having a twisty-turny playmaker/shooter who can get him the puck in prime scoring areas or finish off plays he creates. He's a player who is helped by the ability of others to wreak havoc around the net, be a load to handle along the boards, support rebounds, and can aggressively mount a second or third wave of direct attack (or allow him to do the same).
We may have to settle with giving Pettersson Virtanen for puck retrieval purposes, but ideally, it'd be a better to have a strong, Chris Higgins-esque high IQ puck distributor who can also retrieve pucks. Gaudette or Gaunce would even be better fits with Pettersson than Virtanen if we're strictly talking about stylistically, IMO.
Frankly, if the goal is complementary skillsets, I'd much rather keep them as far away from each other as possible (and Sutter far from Pettersson too) and instead try things like
Baertschi - Pettersson - Boeser
or Pettersson - Horvat - Boeser
or Eriksson - Horvat - Virtanen
or Gaunce - Gaudette - Virtanen
or Gaunce - Sutter - Virtanen
If Pettersson's immediately at a playing level that can justify it, I would argue that he should always be stapled to Boeser, because their games really seem like a match made in heaven that complements each other perfectly.