But to say they're on very similar trajectories is to ignore that Nichushkin's trajectory took an exponential spike, or to assume that the same would happen to Kakko.
It's being framed as though Nuchushkin improved every single year into the player he is outside of that one season. That's not what happened. What happened is that he went from a career-high 0.38 PPG in 2021 to 0.83 PPG in 2022. That type of increase in production is exceedingly rare.
It's the same thing as the Lehtinen comparisons. Both players scored at a rate Kakko has never approached.
Most forwards' primes are in their early to mid 20's in terms of production. Anything can happen. Kakko can win the Hart someday. "Can" is not a basis for projection.
That's not entirely accurate. Nuchs career prev high was .43 ppg as a rookie and then .42 in his D+3. You could see talent was there that he had to put together. Even after Dallas gave up on him he had injury issues, his games played were erratic, no seasons close to full (like his D+1 and D+3). I can't say how frequent or infrequent it is for a player to take a dramatic jump from his previous high but I doubt it's unheard of.
Kakko's path SO FAR has been similar to Nuch's, not identical, similar. Including the downer year Kakko is having this year. Players don't reach their primes till 25 or older, especially bigger forwards and Dmen. I'm not projecting he becomes Nuch or takes the same exact path, I'm saying his development so far is not dissimilar, and that thinking he topped out in his production at 21-22 is far less likely than that it goes up significantly by the time he is 25. Not only "can" Kakko become a 60 point player, its also far more likely than him having already had his best year. (or winning the Hart, hahaha) The people who thought Nuch had topped out at .42-.43ppg were wrong... and had they been right that would have been the outlier.
Edit: if his chronic health conditions have taken a turn for the worse, and are responsible for his weak start this year, then everything I wrote goes out the window. I kind of doubt that is it, but you never know.