Farrell should not have been the last pick of the fourth round, in my opinion. I had him exactly 50 spots higher at #74.
In a sense, you are getting a player whose better than the draft slot. I would not look at Farrell as a late 4th as opposed to a 2nd-3rd round pick that fell to the last pick of the fourth round. I don't think his odds are as long as most players picked in his draft slot. I think it's entirely possible he turns into a middle six forward in the NHL. Maybe he could maximize his upside a little higher on a second line.
Saying all that, his stats are impressive but they need to be put in context. He plays on the best team in the league, a real powerhouse. Chicago Steel are the equivalent of CSKA/SKA in Russia. They are starting to become the best team in the league just about every year. This was supposed to be a down year for them, and they are the best once again. He's also the oldest NHL prospect on the team. I think there might be one or two players on the team who are older than him, but he's pretty old for the league, given his age and ability. I haven't thought he's really dominating out there either. He's doing about what I'd expect, and then you adjust for context with the team he's on and his age to get the incredible statistical totals he's putting up.
Farrell plays a game that you can see getting less effective as it translates up to higher levels. The question with Farrell has always been how dynamic his offense is for his size/skating. His offense is pretty good, but it's not great. His size/skating is not going to keep him from the NHL, but it's probably a little below average. Good hockey sense, works hard, good defensively, but he's an undersized guy whose not a great skater and not a great scorer. There are going to be questions how his game translates.