I'm not saying dress 7D unless there is significant doubt about the ability of Carlson or anyone else to finish the game. Basically I don't want another situation like Alzner in Game 6 last year, where it absolutely would have made sense to scratch a forward to get another defenseman in the lineup. Alzner's groin was being held together by duct tape and players like Wilson, Winnik, Richards, and Chimera were largely ineffective for most of the series. Would have made sense to scratch one of them and insert another defenseman last season. And if that situation arises again (mainly w/r/t Carlson since he's dinged up), I'd rather dress Schmidt just in case. If Connolly, for instance, were scratched I'd feel comfortable double-shifting Ovechkin, Johansson, and Winnik in Connolly's place on the third line.
I see what you're getting at here, but it's the kind of thinking I hope our coaching staff avoids. "This line should play more, that guy should start over that one situationally, maybe 11F/7D, let's proactively tinker in anticipation of what the Leafs might do," and so on.
I don't think we should change a thing. If there's a question about Carlson being up to it, he should sit, someone else should take his place, and we should proceed as usual. Distribution of minutes should remain the same, we should be no more reactive to our opponents than usual, and should generally just not vary from the plan.
Don't fix what isn't broken.
I'm comfortable with our depth on both ends. I think we can weather injuries better than most teams. I don't want to see us trying to overcompensate for every perceived mistake or momentary weakness. I don't want Barry overreacting prematurely and shortening the bench or overhauling systems. I want to see our guys being given every chance to overcome and adapt.
We've assembed our best team ever. It's on them now. Stick with the gameplan and let them do their thing.