These examples don't work. Hunter gatherers didn't suffer, and the other two are in outlier bad situations. Set them free in a stable situation and they'll live happy lives.

If that description of wild mice is accurate, there is no happy free life. The baseline is very different. I'm not going to try to say how that should affect the rest of the ethics, but it's an important point to consider, and not as easily dismissed as your examples would imply.