Australia: Kim was a common male name

Kim is also a shortened form of Joachim.

Kim actually is usually a family name, but it's written first.

Kim Jong Un, right :)

Very likely it's their family name. Kim is the most common family name in Korea. Most Korean given names are two characters (=2 syllables) and more difficult to pronounce and memorize for westerners. And because of the space inserted between two romanized syllables (Jong Un), they are often misunderstood as middle + given names.

The current Kim's dad didn't help here giving his son a name that's so similar to his own.

In Britain we had the very famous MI6 Intelligence office Kim Philby who was also a Russian spy, he was a key part of the Cambridge Five spy ring.

What I didn't know until just now is Kim was just a nickname. He was Harold Adrian Russell Philby and apparently Nicknamed "Kim" after the boy-spy in Rudyard Kipling's novel Kim[2] which surely foreshadowed his career!!

[1] https://www.bbc.co.uk/news/uk-24803131

[2] https://en.wikipedia.org/wiki/Kim_Philby

Kim is the name of the protagonist of one of the most popular boys' novels of all time, and there are a number of examples of well known male Kims from the twentieth century.