* A bevy of writers
* A coterie of writers
* A guild of writers
* A fraternity/sorority of writers
* A fellowship of writers
* A league of writers
* A society of writers
* A company of writers
You can also get creative and use other collective nouns that fit the context, like:
* A swarm of poets
* A hive of novelists
* A gaggle of journalists
Ultimately, the best collective noun for writers depends on the specific situation and the desired effect.