Balrog vs 200 000 dwarves ?

[Galadriel55]

Originally Posted by Lalwendë

Perhaps it was known by those few who did know/guess that the Balrog might be in Moria that Gandalf was the very best placed opponent for it? And that they didn't want him to face it? After all, it was known what it did to Glorfindel in the escape from Gondolin.

I doubt that anyone knew that it was a Balrog, or Gandalf, of all people, would have known. Instead, Durin's Bane and Balrog seemed like two unrelated entities. Aragorn's prediction, in my eyes, was just foresight, not knowledge.