Are you serious?
You really think a combat system in which you could precisely aim at different body parts would be less lore friendly than a simple hack'n'slash action system? I can't express how much I disagree with you here and you can trust me as well, I know everything about the witcher lore. I'm an extreme fan of the books of the lore, even more so than the games...
And there is nothing wrong with being inspired by other games, that happens all the time in video games. Witcher 3 is inspired by Skyrim as well (for its open world approach as well) without being a rip-off or copy. To be honest, almost every system you could come up in video game development has already been done in another game in another context.