What if we tried to create a movie script together!

I agree that we need to describe the area of action. For starters, I will post my excerpt, and perhaps later I will even create a map.
Now, the esteemed reader can easily imagine the piece of land on which our story unfolds.

Colleague, that's good, just don't forget that we are describing the entire world, not just a small piece of it. Soon, I will try to scan and provide Perumov's version, which he created for his "Mage."
As I assume, we will have a more global scale. And therefore, we need to use larger distances in kilometers.

for continuous clashes with demons,

Don't forget that there are no demon lands in the time we are describing. Demons are in Hell, and only small groups infiltrate the surface.

The war with the demons united the wood and dark elves, forcing them to forget, at least
for a short time, about their own animosities.

Perhaps it would be better to talk about disputes or animosity (singular). And then, in the time we are describing, the elves are again at odds, sometimes secretly, and sometimes openly.