In your scenario, Group A got dragged into the mud by Group B. If they wanted to stay ethical, they would've been "dominated". They chose strength and survival over staying "clean". Like I said before, it's fine, and I'd probably agree with it. It may even be the lesser of two evils. I need to reiterate that I'm not disagreeing with Group A's actions here to resist. I'm just saying accept the fact that you're probably trading your ethics for it.

I think the key difference between our points of view is how strictly we want to define "being ethical". I'm pretty strict about the definition. At the same time, I'm okay with being labeled unethical from time to time.