Greg responds...

I have nothing to do with the choices made on Smallville, and am largely unaware of them. They hold no relevance.

In the Earth-16 continuity, male names are hyphenated. Female names are not. So Jor-El and Lara El. Dru-Zod and Ursa Zod. Unmarried females use their father's full last name as a surname, e.g. Faora Hu-Ul.

These choices - while obviously (and perhaps unfortunately) paternalistic - had the virtue of clarity and consistency for us, on the show, while lining up with tradition from previous comics continuity.