Kapanen has produced like a top-6 forward in the AHL, FEL and WJC as an 18/19 year old. That's actually quite impressive. He was thought of in the same class as Nylander at draft time but fell a little bit. He was moved as the main piece for star forward Phil Kessel. A guy like Larsson has not done one thing to exceed Kapanen in value, he probably has less.
Brown is 22 and only has 7 NHL games. But, guess what, Montour is 22 and hasn't played a single game at the NHL level. What elevates Montour's status above Brown's? They've both seen that major development spike over the past few years.
I don't want to trade the Leafs prospects for the Ducks D prospects, either. I am just acknowledging the value is closer to what I'm proposing then Ducks fans are asking. I'm mentioning prospects that have almost identical value to one another, even though I don't want to trade them. Ducks fans are asking for literally the best prospects in the world for these guys.
It's like Habs fans asking for JVR for Juulsen. Literally asking for top of the lineup talent, for stuff way way down your list.