They shouldn't follow the consensus, b/c that guarantees mediocrity.
They should follow their board.
Now whether they're good at player evaluation will be revealed over the next couple years, but if you're going to follow the consensus, just fire all your scouts and get an AI program to aggregate all the "consensus" opinions.
Buium was the 6th D-man picked, which suggests NHL teams see some flaws that are more likely to be exposed at higher levels. It's not 20 years ago, teams love offensive D-men these days. Doesn't mean they're right, just that he wasn't a slam dunk or he'd have gone in the top 5.
Luchanko was a late riser, but wasn't going to get much past #15, with at least two teams prepared to take him. He's got the perfect skill set for today's NHL, but whether he can translate those skills to the ice remains to be seen.
If they were just picking for position, they should have taken Helenius, who's a pretty safe bet to be a 2C down the road.