Btw have you guy check the recent video about 'Forever Winter' game for what to expect ?
This can help give you guy insight of what being a scavenger was like when in middle of war between some factions here (some scene seems fit right in for warhammer 40k imperial guard).
Although I don't like Asmongold (except his legendary editor), but this video do show the game quite well in one go there. Also recommend watch 'Riloe' two other video on it like 'This "ANTI-SHOOTER" game is beautiful and horrifying - The Forever Winter' and 'The living War Ecosystem where you don't matter', they give good insight into this setting and the author could take some inspiration for Hive people or similar
View: https://www.youtube.com/watch?v=EODjhsjTFLk
Bonus info on game: Something the trailer didn't quite make clear is that the warring armies will actually ignore you even as they run right by you, as long as your threat rating is too low to be paid attention to - they have bigger fish to fry. It's only as you make yourself a big enough problem that they will begin to divert squads and forces from their operations to respond to you.
In a way, Forever Winter feels more alive than most games precisely because it ignores you, because it happens around you without your input. Until you've stepped on just the wrong toe.