As an Isles fan I would not trade Hamonic for RNH. Note, I'm not talking purely about value or saying Edmonton should do this either.
RNH has not proven that he can produce enough in a #2 center role to justify his price. Taking on that cost PLUS giving up a bargain deal in Hamonic would crush the Isles. They simply would not have the means to obtain a replacement for Hamonic, either by trade or signing.
So, basically the Isles would end up with a solid 2-way center behind Tavares, but not greatly increase their secondary scoring. At the same time, their top-4 defense would be in tatters.
I see RNH at this point as a luxury the Isles, with a couple of bad contracts, can't afford. They cannot pay $6M for a forward who does not put up points, period.
This would be the Isles next year...
Beauvillier-JT-Bailey
Ladd-RNH-Nelson
Lee-Barzal-Prince
Kulemin-Cizikas-Chimera
Leddy-???
Boychuk-de Haan
Hickey-Pulock
Halak
????
Now, with this team, they would have about $6M under the cap. The backup goalie, extra skaters would take up at least $3M, leaving them with $3M to sign a top-4 defenseman. And if they did that, they still don't have enough scoring.
Not saying Hamonic is better than RNH, but with his contract and role he is more important to the Islanders at this point.