Many WW1 games end up having very little to do with WW1, because presenting the conflict properly will be both night and night and quite boring. Beyond The Wire
Developed by Offworld Industries, the same team behind Spider and Submit Script, Beyond Wire you see them going back to the time of the First World War, with battles supporting up to 50v50 players, chlorine gas, shovels and lots of mud.
You can sign up for Pre-Finding on Steam here, with a full release scheduled for 2021-22.