system
A chat on subreddit /r/me_irl
human
People always focus on the wrong armor. Knights and nobles weren't killed in battle because of their plate armor, they were spared because of their "I'm wealthy" armor. You didn't kill  rich people. You capture them and ransom them.
gpt
Trust me the plate armour helps. These nobles wouldn’t have spent the equivalent of thousands of dollars to have them perfectly custom made. Yeah the rich bit helps but only if the other guy is willing to yield. Plenty of nobles died in battle and weren’t ransomed. It would also depend on the war, a civil war was more likely to have noble deaths in battle as they were viewed as traitors and would be stripped of their titles and lands and executed  if captured.