Far too simplified an approach. If you gave a GM and his amateur scouting staff a mandate to simply leave the draft with two guys that will make the NHL roster, you end up with what the Kings have done from 2010 to today. Targeting lots of role players that fit a system. And look where that's left the organization's prospect depth. In fact, Lombardi spent half of his bizarre conference call with the press saying the Kings need to change what they're doing at the amateur scouting level. His statements tell me that he is in no way happy with "batting 1000" by getting any two future NHL roster players.
You don't stay a contender if you're patting yourself on the back by selecting Nick Shore and Andy Andreoff. Those are replacement level players and they're part of the problem. The scouts have to do better.
You can draft skill all day long and still end up with just 2 players. Every GM would love to hit on every pick they have, but it's unlikely to happen. Considering there are 30 teams drafting, every team should, in theory, have 7 picks, they're drafting mostly 18 year old players, and the further down in the draft you go, the less likely you are to get one of the top 690 hockey players that are in the NHL, 2 out of 7 is pretty good.
2 out of 7 would be the minimum in terms of success. 1 guy in a draft isn't very good, unless it's a McDavid type player. He'll cancel out some depth issues. I wouldn't say 2 of 7 is batting 1.000, but if you start getting to 3, or certainly 4 players from a single draft, that's exceptional.
If every team gets 2 out of 7, that's 60 players from a draft. You can go to an exceptional draft, like 2003, which had 9 rounds. The 60th player on the list in terms of games played in the NHL is Zack Stortini, with 257. That's barely 3 years in the league. Go to 1999, what everyone says is one of the worst drafts in NHL history, and the 60th player on the list is Nolan Yonkman, with a whole 76 NHL games under his belt. Some years you just don't get a good overall draft class. Other years, you completely crap out, like the Kings did in 2004.