A note...
and a revision; a revision which CJRT arguably echoed for the 1977 Silmarillion, since...
But you just read it! Why do I have to do the work... [wanders away]...
... [eats snack, returns] okay, if the Silmarillion index reference pages are complete, then there are no references to "many" Balrogs. Which makes sense to me, as why would CJRT alter a reference to hosts of Balrogs (or whatever), and leave some other reference indicating very many.
Actually, I know I've written a post concerning the Tolkien-made revision to AAm, including instances that were never changed by JRRT himself (for whatever reason), compared to CJRT's revised wording in the 1977 Silmarillion. It might even be here at BD somewhere, but I can't recall at the moment.
Anyway, as I said, there are instances of the anglicized plural (Balrog-s), and this "some few" survived text (with respect to the War of Wrath), and now I'll add that we have one description of "another" Balrog at one point, indicating two in the scene...
... or at least two, if you like