People drafted in the top 15 picks in the NHL Draft are usually good bets to become NHL players. Some first liners, some second liners, some third liners.
The OP was in 2014... Lets look at that draft:
Ekblad - top pairing D
Reinhart - 1st/2nd liner
Draisaitl - 1st liner
Sam Bennett - 3rd liner
Dal Colle - 4th liner / AHL
Virtanen - 3rd liner
H. Fleury - bottom pairing D / AHL
W. Nylander - 1st/2nd liner
Ehlers - 1st/2nd liner
N. Ritchie - 2nd/3rd liner
Fiala - 2nd liner?
Perlini - Bust
Vrana - 2nd liner (Hello, he is ours now!)
Honka - Bust
Larkin - 1st/2nd liner (Well Drafted, Our favourite player)
HM Fabbri (also ours, drafted 21)
Only 8/15 are top 6 F's or top 4 D men.
The odds get much much worse past round 1.
Bottom line is People were wearing huge rose covered glasses to list a future lineup of prospects that included so many 2nd round picks.
I believe we should be very lucky if 1 out of every 3 2nd round picks even makes the NHL, let alone develop into a top 6F, top 4D man.
But that is where we need to hit homers to speed up this rebuild.