The last hit thing should never appear outside of single player games, where it obviously either doesn't matter or the single gamer playing the game can control it perfectly for the party by micromanagement. Anywhere outside of SP, be it a game or a novel/manga, it's pure bullshit. Some isekai authors are aware of that and make fun of it, in a manner of speaking, but that, then, begs the question of why the author included it in the first place. I'm not the greatest connoisseur of Japanese RPG games, but could it be the Japanese studios never use a different system in their games? The Japanese are rather extreme traditionalists, so I could see them stubbornly sticking to it.