Board Thread:Fiction Universe Discussion/@comment-31573863-20170811084952/@comment-47205-20170811085622

It's absolutely okay to write about wars that have nobody else's fictions involved. Allowing other people to join in has both advantages (it'll feel more like you're part of the community) and disadvantages (you might have to rely on other people being available to write stuff, as you mentioned), so whether you decide to do so is purely a matter of your choice.