Agree, I doubt murder was his intention but I am certain he set out that night with the intention of raping a girl and that it went wrong and resulted in Libby’s death, whereas Sutcliffe and Bellfield and Halliwell etc set out with the intention of murder
I agree that murder probably wasn't planned and that something may have gone wrong, but also remember that there are still plenty of people who wouldn't view going out to have sex with someone who is very drunk as rape. He may not have seen anything wrong with it and may have done it (without an issue) on many occasions before.