The Recapture of north-east Beleriand

[Macalaure]

I think he would have, yes.

I think so, too. There was a bond between Fëanor's Sons and the Easterlings even before the Union was in planning. And they proved faithful until then.

And had it been rejected, defeat would have been equally inevitable.

Here I'm not so sure. I don't want to spoil the rememberance of the faithful Easterlings, but at least after the new men from the east arrived, they were severely outnumbered. Below the line there were more of them on Morgoth's side than on Maedhros'. Of course, hadn't Maedhros asked them, maybe they still would have fought on Morgoth's side.

Getting back to the blasphemy: A few lines before "Yet neither by wolf..." Tolkien writes: "Some have said that even then the Eldar might have won the day, had all their hosts proved faithful."
Some have said? Might have won? Maybe it's not that certain at all.