Well if we look at goal production they had identical draft years and Ras did it a league which, statistically speaking, translates better to the NHL. Svechnikov did put up significantly more assist though I speculate that some of that comes down to usage.
It sounds like you agree with this But puck skill doesn't = ceiling. Not that I'm comparing Ras/Svechnikov to these guys but Drouin's skill and fancy edge work don't make him better than Toews/Bergeron, not yet at least.
Ceiling is more so about how well a guy can translate his own skill set. A huge, smart player from a tight checking league with good puck skills and skating ability is going to have a very high ceiling. Ras is the hockey equivalent of a 5 tool player. Being that he is a centre I also consider that as part of his ceiling.
Ras has 40 goal, two way C potential IMO.
I think a lot of us simply disagree with the notion that his skill level is nearly this high. Rasmussen had a goal heavy, PP heavy stat line that involved putting up very few ES 1st A. Most of his goals were scored within a few feet of the net. I don't question his ability to continue to score that type of goal in the NHL as he'll still be a physically dominant force and his wrist shot appears to have a quick enough release that he's perfect for cleaning up around the net...however any player that struggles to put up decent assist numbers, especially at even strength, in juniors will likely struggle immensely at the NHL level. Anyone with ES numbers as bad as Rasmussen probably lacks some of the vital skills to succeed at the NHL level. In Rasmussen's case I think its largely that he has very mediocre vision/IQ/creativity as well as average passing abilities. On top of this his shot is only good and he's a good skater for his size, but he's still just an okay skater. If these traits are mediocre in juniors it is unlikely for him to be much more than a net front guy at the NHL level.
Its sort of like how D who are less than .5 ppg in juniors essentially never make the NHL...and those that do are generally third liners. Even if you draft what you hope to be a defensive defenseman they should be at least 0.5 ppg in juniors. Any defenseman with numbers worse than that probably lacks the puck skills and passing ability to move the puck effectively at the NHL level. They turn into defensive liabilities as they are unable to clear the puck from their zone and create numerous turnovers. Thus teams drafting large defensive defenseman with poor offensive stat-lines almost always end up with a big guy that is useless because he lacks too much skill.
From watching Rasmussen play I have hope that some of the issues in his numbers were related to usage. He was relied on almost solely as a finisher and rarely did he play with the puck on his stick in a situation where shoveling it towards the net was an ineffective option. Furthermore last year his production was much more balanced and he occasionally has a nice pass. However I definitely contest the notion he has a high ceiling simply because he's big and it's possible for him to hit his development out of the park in every other area. I think a player's ceiling refers more to what someone could reasonably be expected to become (using Drouin as an example his ceiling is probably a flashy 100 point pure-offense winger. He could develop elite defensive abilities and become a 1C, but that would be an unreasonable expectation. It's simply not his play-style and thus should not be considered his ceiling. Similarly expecting Rasmussen to consistently contribute offense outside of net front PP is unreasonable IMO). Obviously anyone can wake up one day and be much better at hockey than anyone would have ever expected. Surprises occur, but with Rasmussen I genuinely think his ceiling is somewhere around a 3C+PP, 15-20 G and 30-40 points, essentially all of which come on the PP. I simply think he lacks too much skill to be capable of centering a scoring line effectively. I see him more as a 1-tool player that's just okay at everything else. He could surprise me...I certainly hope he does.
Svechnikov on the other hand has always showed excellent puck skills and playmaking abilities. Furthermore he has great size and a nose for the net. I don't think he'll develop a great defensive game and I doubt his passing game will be anything special in the NHL...but it is good enough in juniors that we can expect him to be adequate in that regard. I see him as having 1W potential, with 20-30 G and 60-70 points. That to me is a much higher ceiling than Rasmussen.