Why not Ecthelion?

[Galin]

So just, because he refers to Glorfindel's battle with 'demon' hardly implies he planned to change it from a Balrog to some other beast.

And incidentally, to be fair to the other person who raised the possibility, Tolkien actually appears to have crossed out the word Balrog in one instance [in the late text concerned], as well as employ demon throughout. I can't really easily explain why he should feel the need to do that...

... although again I still don't buy it myself [even if Balrog numbers were drastically reduced]...

but let's not [including me, if I have] simplify this person's suggestion of a possibility

And that's all it was, if I recall correctly.