I don't entirely agree on your angle. but it's defendable if you consider Cooley/Savoie/Slafkovsky/Nazar as potential 1st liners, players that dictate the game.
Otherwise you definitely take the first pairing D ceiling prospect over a 2nd liner.
Personally I'm not ready to say those forward prospects (meeting let's say 80% of their ceiling hopefully) are shoe-ins for the 1st line, Slaf being the most likely imo.
Your statement is sometimes true but shouldn't be considered gospel truth. Look at the Sergachev draft (2016) - the only first pairing D after pick 16 (Chychrun) is Adam Fox with a whole bunch of misses in between. 2017 is even worse with *maybe* David Farrance past Heiskanen/Makar. 2018 doesn't look brighter. Even the incredible 2015 draft doesn't have a top 2 defender past Chabot at 18. For top defenders you also have to pick early now - the Shea Weber and PK Subban picks are an outdated reference.
By our 2nd round pick the only Ds with legitimate 1st pair potential still available might be limited to Hutson (smol boi), Bichsel (mostly defensive but yuge), and Lindgren (big if). Nemec/Jiricek/Mintyukov/Mateychuk/Korchinski/Pickering I suspect will be gone and I wouldn't trade up for the last 2. Definitely more than 6 Ds drafted in the first 32. Absolutely no point for the Habs in drafting a defender with a 2nd pair ceiling, at this point. Go big or go home. If that's what you see in Nemec and Jiricek, I understand your position.
In my opinion this draft will have sufficient offensive quality at around pick 32 that I would prefer:
Nemec/Jiricek + Goyette/Ostlund/Kulich/Firkus/Gleb and other falling Russians
vs
Cooley/Nazar + Hutson/Bichsel/Lindgren
Slaf is the wildcard, I don't know yet.
Anyways, BPA.
And let's suck again next year.
I agree that we don't need any more depth defencemen. We've got tons of them. Go big or go home.
But I think you missed the main point of my post. Or maybe I didn't state it very clearly. First pairing defencemen have regularly been found with picks outside the top 20. Not just serviceable, unimaginative journeymen but genuine NHL stars. The tricky bit is that at the moment that these future stars were picked, they were perceived as much less.
When Shea Weber was picked the second round (47th overall) in 2003, do you think Nashville and the rest of the league knew he'd anchor for a first pairing for the next 15 years. Of course not. Or he would have been picked top 5.
PK Subban, Chris Chelios and Larry Robinson were all also chosen in the 2nd round. Andre Markov in the 6th. Together with Weber, these four players have been the heart and soul of the Habs' defence over the past five decades. None were top picks.
The odds-on Norris Trophy favorite this season, Roman Josi, was drafted in the 2nd round. Last year's Norris winner, Adam Fox, in the 3rd. Ditto for Kris Letang.
That all these lower picks turned out so well is not only a testament to savvy drafting. It also shows that when a defenceman is picked at the age of 18, it is very hard to predict how he will pan out. This is much more true for defencemen than for forwards. For every Nikita Kucherov (round 2), there are many more Duncan Keiths (round 2), Zdeno Charas (round 3), and Niklas Lidstoms (3rd round). All Norris winners.
The list is long and not necessarily "outdated". It takes time to for most defencemen to mature into their final iteration. Generally speaking, longer than with forwards. Which makes looking at trends during the first few years after a draft a bit misleading.
So without being particularly familiar with the prospects in this year's crop--truthfully, who is?--I say emphatically "give me Cooley!". Or Wright! Even Slafkovsky, if he's the real deal. There is a crying need for top drawer talent on offense and we will not get it other than through the draft. Hopefully, we will not be picking this high for too many more years, so let's not squander this rare chance to get a bona fide star.
And with our three other picks in the first two rounds, maybe we'll get lucky with Tristan Luneau or Ryan Chesley. It happens more often than you'd think.