Dragons vs Balrogs

Anyone nothiced that all the Dragons ever killed in Middel-earth were offed by humans? Turin killed Glaurung, Earendil killed Ancalagon, Scatha was killed by Fram, Smaug shot by Bard.....

Sure, Glorfindel tackled Balrogs, and Fingolfin went toe-to-toe with Morgoth himself, but Dragons seem to give Elves the willies.....

I also noticed that at the Nirnaeth Arnoediad, Azaghal and his band of merry dwarves saw off a troop of dragons. Stood up to Glaurung himself. But in the 3rd Age, a single Balrog appears in khazad-dum... and the Dwarves are forced to evacuate. What gives?

If Balrogs are that much more powerful than Dragons, why would Morgoth bother breeding them, especially when the operation would dilute his powers even more, if I've understood Michael Martinez's article "Understanding Magic" properly.

And when Glaurung, Morgoth's first working prototype dragon showed himself prematurely, I'd have thought the Elves would suspect something was cooking in Angband. How come they didn't develop any anti-dragon defences? Even after Dagor bragollach, the elf-kingdoms were mostly intact. They'd know about dragons for sure by then. And even after Nirnaeth Arnoediad, Gondolin, Nargothrond, were still there.

But then maybe they did. Bard's Black arrow may date back to the first age, and designed as a dragon killer....


Music.... maketh the Ainur..... come together.... yea.....