Nice strawman you made there. I never claimed that Aho is a better player than Kopitar. Kopitar is at the moment probably two tiers above Aho, Rantanen and Barkov. I have said that Aho was in my opinion a better player than Rantanen, and I still believe that it applies at the moment in bigger rinks. But in the NHL I see Aho and Rantanen pretty much at the same level at the moment. Rantanen benefits from his team being so weak with their depth. Carolina definitely has more solid depth, so Aho has more of competition for ice time over there. Also Rantanen is so much readier physically than Aho, which gives him also some advantage at the moment in the smaller rink. But still I see them at the same level even now, and I believe that Aho will be in a few years the better of the two quite clearly, when he gains much more strength and becomes more accustomed to the North American hockey.
I project Aho pretty much to become a player like Zetterberg was at his prime. They both are so amazingly similar as players. Even their height is the same, and as Aho gains strength he will be able to better use all his magnificent tools like exceptional hockey sense, great puck control skills and extremely quick reacting to situations.
I believe that Rantanen might be a 60 point guy at his best, but I'm still not that sure if he will really reach that potential. I honestly will be extremely surprised if in two years from now Aho is not having the clearly better NHL career of these two.
Oh, and in my books Barkov is completely overhyped, and is definitely not among the top 20 centers in the league. He is most probably not even the best center that the Panthers have...