Balrog vs 200 000 dwarves ?

[Tuor in Gondolin]

A figure of 10,000-20,000 dwarves seems more of a realistic maximum,
not only with slow population increase but supplying them with food, etc.
Rohan itself, in a time at the War of the Ring when they had pretty much recovered from past problems, probably had a population of perhaps 100,000
(assuming a male fighting pop. of about Theoden's 10,000 estimate.
Especially after Hollin wasn't a source of trade there's limited trade potential---
dwarves better love eating mushrooms grown in tunnels (like
in southeast Pa.).

The image of an Alien stalking Moria is not only scary- but could be not
that far from Tolkien's conception.

Of course that does bring up the question of how the balrog organized
his orc/troll forces in Moria later. He seems to have been the generalisimo.