Sorry to surprise you. I could have warned you. No, the age of the wood is not really signficant to the plot, but Falco's argumentativeness is. It was handy. Please don't interpret Falco's rough words as mine. It's all in the spirit of rpg fun. Conflict makes stories happen.
Just so you know how this whole thing with "from the north" worked out, your guesses are generally right on, except for the minor point of this having come from the north. You see, the Master, whose name shall not yet be revealed, took a very circuitous route to escape from the south and arrive in unprotected north lands. We're talking very far east, then north, then back west, passing the Iron Hills, the northern mountains, and so forth, arriving in the Hills of Evendim from the north. The Master doesn't have orcs, since they are currently at greatly reduced numbers and in hiding, but he does have men from wherever he could find the type who would serve him and do evil in his name. That does include men from Harad, as well as Easterlings, and bad types from the north, such as Boris from Bree. Hillmen from Arnor too.
Morgoth's citadel is an interesting notion, but who knows where it is? My guess is that it's much farther north than the northernmost hills of evendim.
Anyway, I hope that clarifies things.
By the way, don't expect your words to shut Falco up. There isn't any doing that unless you gag him.
