I try to be good. I'd like that from others.
But when your bubbles intersect and you're in the same game, competing directly, other people's ethics absolutely do constrain the ethics you can choose for yourself while remaining effective. I'm not saying you should sacrifice your principles; I'm saying you should mind the difference between sticking to your principles and winning, accept they aren't the same, and not insist they always are or would be "if everyone just." Because everyone won't just.
Your principles may make you better as a person in some way (they really might!) but that doesn't mean they'll make you win. Not admitting this will make you less effective at defending them.
Maybe I'm getting away from the point of the thread, I don't know.
I guess in my analogy the war has come to the army of swords, like it or not. Team Machine Gun could have chosen to be nice. They didn't, so what now? The answer cannot be, "Well, then they're bad." It doesn't matter if they're good or bad: they're here. They don't care what you think. So what do you do?
And the American Service-Members' Protection Act…
Further, you have dehumanize the attacker. They have agency and don't have to attack in the first place. Even then, your analogy fails because you can disengage from the "attacking force" (quit or not accept an offer) without surrendering in the theater of operations of the professional world.