I think Morgoth's embryonic force of winged dragons must have existed by that time. Had the Eldar and Edain won Nirnaeth, and threatened his stronghold, surely he would have released them. Considering the dismay of the Hosts of Valinor when they were released, their effect on the far smaller army of the Eldar would have been ruinous.
But enough about that.
Quote:
...the Eldar might have won the day, had all their host proved faithful.
(The Silmarillion 20 - emphasis mine)
|
Mandos' prophecy at work. So the sentence could have meant:
The Eldar might have won the day, were they not under the doom of Mandos.
Since the doom of Mandos had taken effect when they rebelled, and left for Middle-earth, the only way they could not be under Mandos' curse was if they never rebelled and left Valinor. That means they would have won the fifth battle were they not there.
Crazy, I know.
It just means victory at Nirnaeth was impossible.
You could have said that earlier.
I was trying to support my statement! Statements need supporting facts, or they'll be like legless Ents, or legless Balrogs.