In D&D you can actually subdue a dragon by not killing it and getting its points to a certain degree. pretty much using the knockout command.
I'd love to see that kind of stuff, but I just don't know that we will. "Each life is of infinite value and merits sacrificing everything for.", I love that idea but hate how it's impossible to play that kind of character. I realize there are limits in a game like this but I really like the idea of being able to cast sleep to stop people from coming to blows or even cleverly taking control of the goblin horde to spare their lives.
I hate to say it again but sounds to me like another game mechanic Larian thought was cool without really thinking about how to properly implement it
What I thought it was, was an option for when a party member is otherwise charmed or controlled. But charm doesn't work like it did in BG2, so I may be totally wrong.