Ah!
Shouldn't this question be asked for any player selected in any round? Even a first round pick is successful if they can't be easily obtained through the means you mentioned.
If a first round pick from one year is on the second line with a third round pick from another year, does that make the first rounder a failure or the third rounder a success?
yes and no, imo.
Ultimately, imo, you want to get as many top 6/9 forwards, top 4 d, and number one goalies out of the draft because those players aren't easily obtainable on the waiver wire, ufa market, or trade market for very late round picks. So if you shank your 1st round pick but light up your 3rd round pick (ex: Brayden point), ultimately who cares what round you got the good player in.
But, you would expect a higher percentage in the first round than the 2nd round, and than the 3rd round, etc...
And, in a particular draft you may find a top 9 forward, but there were so many other good players available after him, that it's hard to consider the pick a success (example Andrei Kostitsyn). Galchenyuk may enter that category depending on where his career along with Rielly, Dumba, Forsberg, Terravainen etc... go.
And, Timmins always says with top 5 picks he considers a success a top line forward, a top pair d or am elite number 1 goalie.
I'm just dead against considering picks like O'byrne successes because he's better than 95% of 3rd round picks. Ultimately he wasn't very useful, so he, like 95% of other 3rd round picks, was failure.