Got the link yet? Of course you have. They are all first names that function equally well as surnames, or vice versa. Henry James or James Henry? George Michael or Michael George? Paul Simon, Simon Paul? Either sounds equally normal, equally correct, though some orders scan better than their opposite. You could find lots of other examples if you wanted to (though after a while, trying to think of dual-purpose names seemed to clog up my linguistic faculties and I was reduced to skimming through the papers and scanning the spines on the bookshelves). They are still in the minority, though. Most of the surnames in the phone book would sound distinctly odd as first names. Cresswell. Eagle. Foley. Longman. They wouldn't sound right preceding something else. Cresswell Jones. Eagle Smith. No, though Eagle Smith sounds as though he might have been a great blues player.
It must create confusion sometimes when you have to introduce yourself, or register for something. I used to deal with a stockbroker called David George, a long time ago. If he gave his name as George would that be understood as his surname, or would the person he was speaking to assume he was being informal and had gone straight to first name terms?
Most of the first-name, second-name examples I can think of are male, when used as forenames. I was pushing it including Stella. While Frank Stella is a famous American artist, there aren't any Stellas in the Colchester phone book. There again, there aren't many people of Italian descent in the Colchester phone book. Perhaps I'm struggling to find examples due to some sort of cognitive bias, but I don't think so. Sinister evidence of the patriarchy embedded in our language?
There is another raft of first names that become second names by the addition of a final S. Williams. Rogers. Stevens. Janes. Richards. Phillips. Edwards. Roberts. Matthews. I slipped Janes in there, but most of these names seem to be masculine as well, and Janes isn't exactly common. Anyway, first names that require extra letters to become second names don't count for this exercise.
Then there are the names that can be male or female. Evelyn Waugh married another Evelyn (unhappily, as it turns out,) and a whole detective story hinges on the fact that a child called Evelyn reappears in adulthood (bent on vengeance) as a woman called Evie. If you are meeting a Stacey or a Kelly for the first time you wouldn't know quite which to expect. A Robin might be a woman, especially in America. Man Ray's assistant, one-time lover and lifelong friend Lee Miller was a woman. Ruby Walsh is indubitably a man, though he is the only non-female Ruby I can think of. More common are the unisex abbreviations. Nicky. Stevie. Sam. Charlie. The diminutive final y or ie gives them a sort of metrosexual connotation when applied to men. I feel as though a man called Nicky would be much more likely to be a hairdresser than a steel fabricator. First names that sound the same but are spelt differently don't count, so you can't include Leslie and Lesley.
Intriguingly, Evelyn, Stacey, Kelly and Lee don't stop at being first names for both men and women, but will do as surnames as well. Imagine being called Stacey Kelly. The scope for confusion would be practically endless.