Heh, yeah, I'm not following the discussion.
This is all more art than science. Proper talent evaluation is the way to go...always. It's not easy, but that's the way to go. A structured league hurts unstructured players. One way, incomplete players don't generally thrive in a well rounded league. That's a big part of the reason why we didn't see a lot of random nonsense players suddenly emerge in the first expansion. The league was full of well rounded players, play was structured, player development followed a model, and the channels to get into pro hockey were (right, wrong, or indifferent) more challenging.
We see the league deteriorate as we get further from the sponsorship era, coupled with vast expansion and the absorption of a minor league into a top level league created a very unstructured league. Unstructured leagues are anti-parity and create random chaos. One way, incomplete players come and go, highs and lows...unpredictable. Weird events (200 point seasons, absurd swings, absurd dominance by the haves over the have nots (two teams owned the Cup from the 1976 until 1984), etc.). Development model gets busted. There was, what, 8 Americans in the NHL in 1973 or whatever and then in 1984 there are 18 year olds straight out of high school winning Vezinas and biting at the Norris...come on. That's silly. Especially because a lot of those guys didn't capitalize on it later. You don't peak at 18. (Well, maybe I did, but an NHL player wouldn't, except for extreme circumstances that don't apply here).
The measurement of this, as it were, can start at the top and be made easier. It's still proper talent evaluation based, but it's easier than trying to gauge the entire league. First you find out how good the players at the top are in the context of the generation before and after them. You start to draw some lines and make some connections about position and player evolution and you get a pretty good foundation pretty quickly. But it takes work. It's not something we can just punch into a calculator real quick unfortunately...