Only trade one of our defensemen if you have to.
"Have to" could refer to a deal you cannot refuse, if you are facing an immediate salary crisis, or if they have lost their spot due either to poor play or (hopefully) one of the young guys making them expendable.
Thus far none of those things have or are happening. If Moore were outplaying Tyutin and we are thinking "holy crap, we have to play Moore on the 2nd pairing BUT cannot afford to pay Tyutin that much to play on the bottom pairing" then you trade Tyutin. But not until then.
If guys like Moore, Savard, Erixon, Murray, and whoever else want to be consistent NHL defensemen, they have to beat out the already established guys there. If they can't beat out those players, they don't get the time.