I genuinely don't see how anyone can believe that Petro wasn't a gigantic contributor to the Cup run. The argument that we might have won the up without him is ludicrous.
He was 3rd on the team in scoring with 19 points in 26 games. He led the team in ice time, playing 38 seconds a game more than Parayko who was 2nd. He was also 3rd on the team in even strength scoring and provided 33% of all the points scored by our D men in the playoffs. And he did all of this without having a consistent D partner. While Parayko and Bo played 427 minutes together at 5 on 5, Petro didn't get 200 minutes with any single partner. He had 179 minutes with Eddy, 139 with Gunnar, and 108 with Dunn. He consistently excelled with whoever Berube put him out there with.
There is just no reasonable argument that Petro wasn't the Blues' best D man in the playoffs by a large margin. The Parayko-Bo pairing was fantastic and contributed a hell of a lot to the Cup win. Neither individually contributed anything close to as much as Petro did.
I believe that the window as a true contender closes without him. We're not all going to agree with that, but your argument that we're fine is just based in delusion if you can't recognize that Petro was crucial to the Cup win. We won the Cup by one of the slimest margins in the cap era, becoming just the 2nd team to lose 10 games on the way to a Cup. Acting like we could have plugged an average top 4 D man in to replace Petro's 60 point pace and strong defensive play is just absurd.