I would phrase it as Sakic and Roy have improved their ability to identify depth pieces. When Roykic came in, the depth additions were Cliche, Holden, Guenin, Talbot, Bordeleau and later Stuart, Redmond, Berra (I could be missing someone). That is partly due to lack of available options out there. But Avs missed plenty of great opportunities to add better pieces to surround the core.
When I think of "Depth", I think of it as "options". Nearly everyone you listed were players that were immediately plugged into the lineup when they came to the Avalanche, usually because they were "better" than the players that would have otherwise played.
Now, yes we have those same guys you mentioned, but on top of that Everberg, Rendulic, Martinsen (who, through the 2-Day camp, appears as if he'll be given some good opportunities), Comeau (replacing McGinn who we practically didn't have at all last year), Winchester (who I still believe was meant to take Cliche's spot), Hamilton, Hishon (some love him, some don't "get the hype"...I think he's more in the middle), and perhaps even Skille. And that's just forwards, and that's not mentioning Rantanen. On the Defensive side, I think it's even more prevalent because the only 2 players that would have been worth a call-up last year, Siemens & Noreau, were injured at the times we would have been looking at calling them up. But now, we have Zadorov in the Top-4, have Gormley who is likely to at least make the opening night Roster, and then Bigras, Geertsen, Siemens, and Noreau as players who could potentially see time with the Avs (Geertsen perhaps not, but I don't think there's a doubt that he'll be a "favorite" of Roy's)...of course, some bad things would have to happen for them to see time with the Avs, but the point I was making is that they would be better players to bring up than the likes they'd had in the past (Hello Karl Stollery!)
Just saying in the past, it's possible (not sure how likely though), that Roy played at least SOME of these guys because the alternatives weren't as good as they are. I think we forget sometimes that our depth guys we would bring up in case of injury were players like DVG (nothing against him, but he was nothing special) and Stollery. In 2 years, the Avs have come pretty far in replacing the depth throughout their system. So, like I said, it may not happen, but I believe we're starting to see more of how Sakic and Roy want this team built, and with the newer players they've brought in, there's more of a chance now, than in the last 2 years, that some of those scrubs we complain about could lose their spots.
