Try to get some inspirations from Trenches, in their game, they managed to have cartoonish blend in with realism.
Trenches to have wooden plank floors everywhere, along with retaining walls, but you’ve certainly got the right atmosphere going.
though it may not be 100% accurate I recommend making the grass more dead-looking (color-wise), I would also increase fog and increase the rain transparency. A bit of contrast (Color correction) may help pull the scene together alongside the other recommendations