Will it surprise you, that during development I have been listening to "Fields of Verdun" and "Father" by Sabaton basically all the time?
I also discovered the gas mask you give the player looks to be a Ledershultzemaske (I hope I'm spelling that right). It was introduced in Germany in 1917. The French would have used an M2 mask. I don't think you need to change it, though. I just like talking about the specifics, so I remember them more. Last thing, (Sorry I talk a lot) you should check out The Longest Front here on Itch. It's a WWII shooter that I find really fun and Accurate.
So the gas mask in the game is this one: https://collection.sciencemuseumgroup.org.uk/objects/co148735/gas-mask-germany-1...
The british are dating the mask to 1915.
What you have seen is correct, the french soldier (the player) is also using the german gas mask. Thats because of crunch time. So we just used the same asset twice x)
But I could be wrong. Thanks for showing me that! I understand the time crunch, and if i'm being honest, I kinda like the german masks better