EJ is currently about as good as J-Bo was last year. He is not an elite D, but he is absolutely an average-to-above-average top 4 D man who can comfortably give you 22 quality defensive minutes a night. EJ plays more minutes than any of their D when healthy, is playing a more shutdown role than in the past and is still a pretty darn good D man. He is not an afterthought to that D group and acting like he is just some mediocre, sheltered guy isn't accurate. Cole is nothing special, but he has been an excellent complimentary piece this year when paired with objectively better D men. He has 14 points already, an expected +/- of +3, adequate possession numbers (total and relative) and is doing all that while starting 66% of his shifts in the D zone. He's not playing any worse than our complimentary D like Gunnar, Ed and Bortz did last year. Since that is his role, he shouldn't be viewed as a liability and a reason they can't be successful.
Their D is young and I wouldn't put my money on them to win 4 rounds. But I think they are absolutely good enough (when paired with an offense that is absurdly good) to win 2 or 3 rounds, which is what we are talking about. Barring a regular season collapse for one of us, I don't see the Blues or Avs falling to the Wild Card and moving to the Pacific. So we're talking about whether their D group is good enough to hold up for 2 rounds, not if they are good enough to still be doing it in the 4th round.