Offense is nice and all but man, this kind of defense is so underrated. Hedman makes smart plays but you see at least a "flashy" defensively play from McDonagh a game. I never watch Doughty that much but if he's even better than current McDonagh at this part of the game I seriously see the arguments people have been making.
Hedman's flashy plays are normally against the rush (I think he's the best guy at defending a 2 on 1 in the league personally). He plays - not passively - but reactively in the defensive zone, while I feel that McDonagh's style is more assertive in the Dzone.
I would note that there's a give and take with that. I don't think I've ever seen Hedman out of position in-zone (he is obviously subject to some bad pinches or the like, but in zone he always seems to have his man), while I have seen McD get pulled away from the play a bit. Also - I think Hedman's D is "boring" in that it's normally just breaking up a cycle with his reach which is never going to make a highlight.
I think McD and Hedman are close overall in D but they certainly bring different things to the table back there. McD is fantastic on the takeaways and board play, Hedman is great at position and disrupting cycles. And I think Hedman is better on the breakout between the two.
I mean, we have two #1s who can each play against the best in the game. That's an amazing luxury to have.