Please, set the record straight.
A) Players don't stop developing physically until 25-27.
B) In that time, players experience different rates of development at different times. So just because theoretically one is better at 19, but the other is better at 20, it doesn't follow that the gap between them will continue to grow at that point.
C) There is no better evidence than our team these past 2 years, to prove that prospects around the league are going to be on display in drastically different scenarios.
I appreciate your enthusiasm for Necas, and your bold stance on Rasmussens ceiling, but it's hard to have too much faith in an assessment that doesn't seem to take the above factors into account. The lack of detail in your assessment of Necas, further indicates to me that there's a lot left to be seen, as to how these players careers play out.
Beyond that, any given year, there are going to be players who's stock rises higher than their draft position. Again, I appreciate you pointing to Necas as one of those players, but I don't really see how that should affect my perception of Rasmussen. The reason it's fun to look back at drafts and reshuffle rankings, is because picking 17,18,19 yo players across the globe and ranking them is an inexact and difficult science. Same goes for 20 yo's.
Honestly, I love Peterssons game, and he's producing at a ppg clip. He's head and shoulders above these two guys. But if you told me he got a hip injury at age 22, and a knee injury at 23, and he fell back to the pack, that wouldn't be shocking.
It's bad hockey talk to say that Rasmussen will be better than Pettersson when they're 28, or even has a half decent chance of it. It's also bad hockey talk to say that there aren't ways that Rasmussen can catch up, and be a prime player for his age group, and win match ups against premier players, like Necas might be, or Pettersson is.
I don't disagree that Necas looks like a great prospect, and the real deal. I don't agree that fact should make us insecure about Rasmussens development or that we should try and invent a time machine to redo the draft.
My expectation for Rasmussen is to be near a Mats Sundin level by his mid 20's. I realize that this is purely hopeful speculation and forecasting on my part, so I would offer it in a discussion as an anecdotal opinion of mine, not a clear cut fact. Likewise, a good AHL season, and a good start in the NHL is well enough reason to pick out Necas and have an ultimate faith in him. But you also have to admit to the anecdotal properties of that claim, due to the unpredictable nature of developments in people, athletes and sport over the course of the 2 decades that these players careers will be playing out across.