Or, Option C, realize that system balances have NOTHING to do whatsoever with world building and that the system is designed to create ADVENTURES, not worlds, and not worry about it in the least.
I mean, good grief, it's pretty much part and parcel to the genre. The Ring Wraiths could obliterate Bree. Kill every last man, woman and child in every town they come to on their way to find the Hobbits. Without so much as breaking a sweat. So, why are there any living creatures left along their path? Well, genre conventions. Monsters fight the heroes and vice versa. We don't worry too much about the background, because, well, it's the background.
It's funny, you get TV shows like Hercules and Xena, where our heroes just happen to find monsters everywhere they go. But, surprisingly enough, people outside of those "adventure areas" live pretty much normal lives. And no one questions this. Lovecraftian horrors could destroy the world at any time they choose, but, shock and surprise, they never do.
Again, trying to use D&D as a world building system is an exercise in futility.