Just because a lot of their defensemen fit the profile of players that should theoretically be good defensively, doesn't actually mean that they are good defensively.
I'll give you Tanev, but Kylington, Gudbranson, Hanifin and probably Zadorov are all varying degrees of not good defensively.
And Ceci, Keith, Barrie, Koekkoek and Bouchard are all varying degrees of not good defensively. If you look at it pair by pair
Nurse - Barrie >>> Zadorov - Tanev
Keith - Ceci <<<< Hamilton - Anderson
Kylington - Gudbranson < Koekkoek - Bouchard
The major difference is the second pair. The difference between the top pair is large but imo that second pair is so much better than ours it’s hilarious. At least Tanev can anchor that top pair defensively, our second pair is just bad. Our defence was worse than theirs last year, both teams defence took a step back but they lost Gio who was on a decline and replaced him with Zadorov, we lost Larsson, Bear and replaced them with Keith and Ceci which is a downgrade
They have stronger goaltending but the big difference between the teams is forwards where we smoke them