@Jethzki Not saying that this is the case here, but some game systems do have countermeasures in them for people that start off stronger than others. In D&D, if you played as certain races in the past editions of the game I'm more familiar with, you required much more experience to level up. You were basically meant to be 1-3 levels lower than your peers for the same amount of experience points because you started with more bonuses than they did.
The problem was, that game is super fuckin heavily dependent on the feats. Your bonus feats for classes and such were super important, and they come at specific levels. If it takes too long for you to get there, your build isn't getting much stronger. All because you have like a once a day ability to cast the Darkness spell for a short duration or something like having an extra +2 to some stat that will only really start to shine once your equipment is sorted out and supporting that boost past normal levels you can get just by leveling early in the game.
For the soldiers, I could see them getting some sort of penalization compared to civilians, because they basically started out fully equipped. The hikkimori girl got her gun from the system, they just had access to them and other things from their day job. Maybe they were acquiring skills at a reduced rate at first because they weren't in nearly as much danger or something like that? Otherwise, that one orc boss type was just way too strong anyway. The main character almost didn't make it there either, and he has plot armor. Buncha no named "red shirts?" They could have simply existed to be killed and set the tone for "nobody can help us, we have to help ourselves."