He was right though, it's extremely difficult to acquire top C's...but where he went wrong is that he never thought critically.
A difficult task, is not an impossible one.
The other problem is he was never willing to just pay a fair price to get a deal done. Everything had to be a bargain and he had to "win" every trade. The only real exception was Subban for Weber, and you could potentially argue Sergachev for Drouin but I think in Bergevin's mind he saw that as a bargain too. He was unwilling to just pay a 1st + Poehling to get a Selke-candidate #1C in his prime to complement Price and Weber. He wanted to do it on the cheap so he tried to go bargain bin shopping with Domi and prayed that Kotkaniemi/Suzuki would work out in time to be big Cs while Price/Weber were still around.
Even in the Canada division year where he went "all-in" it was trading a 4th for Edmundson's rights, bargain hunting on Anderson, trading a mid round pick for a 1B goalie, and signing Toffoli on a discount. It wasn't paying to get a difference-maker like Devon Toews. It was always bargain shopping and simply just paying a 1st + some prospects to get a good veteran player at a premium position was never an option.
Dach isn't quite the same thing but it's the same underlying logic. Hughes and Gorton identified a valuable asset with rare traits who would only get more expensive if he developed into the kind of player they hope he can be. They didn't screw around trying to dumpster dive, they accepted that these kinds of prospects are expensive so they found a way to move a good young player like Romanov and some depth picks to get him. Bergevin would have heard the price and recoiled in horror before trading a 5th and a throw-in for Logan Brown or Henrik Borgstrom instead.
I can honestly say Suzuki could VERY well of been an accident lmao
It genuinely kinda was, the initial target was Glass and Vegas didn't budge so they shifted to Suzuki. Not that it was necessarily a bad thing at the time to be insisting on Glass but that trade looks very differently had Vegas been OK with giving him up.