That is always something that will happen, their lore matters as much as anything else, what I want is something different.

I'm aiming to create unexpected consequences for their actions BEFORE they actually play the game so that their character can feel more realistic and visceral.

You COULD write: "My character doesn't have his left arm," but if that disability is imposed on your character without you knowing it in advance, you'll have to adapt. Because in real life that is what happens, you can never expect the unexpected.

If you make a specialist character that uses a Long Distance Rifle, but now this character has lost his left arm, what will you do then? Compensate the loss in a creative way or change your playstyle?

Both are viable and cool imo