Nailit, (1) and (3) of your examples look like cases where the defence of diminished responsibility may have been run but by rejected by the jury; it reduces murder to manslaughter. In effect, it is that the accused was acting under a temporary insanity brought on by provocation, which had him or her lose their self-control. But (2) seems to be manslaughter . If what you give us is the whole story, the accused did not intend either death or grievous bodily harm, but was reckless only, and so did not have the necessary intent to be guilty of murder. He could have been convicted of manslaughter as an alternative finding on the count of murder.
But the examples do give an indication of how murders, and murderers, differ widely. That is why so many murderers were spared the death penalty when it was the only sentence, and why , at one time, a statute specified the death penalty for certain murders, such as murdering a policeman on duty, but removed it for the rest. It's also why 'diminished responsibility' was introduced as a defence.