In a vacuum, yes this is fair. Given contract and age, absolutely not.
Hamilton is a defenceman. They peak later. He's also 2.5 years younger than ROR. Hamilton seems to be getting better and better. He will be a top pairing d-man for the next 8-=10 years. ROR, is 27, which is when forwards leave their prime. ROR will still be a great player for the next 3 years. However, once he's on the other side of 30, he'll begin to decline. This move would be too shortsighted. Quite frankly, Dougie Hamilton is not the type of player you trade. He's the type of player you build a d-core around.