That kind of combination name is found useful by many Afrikaans-speaking parents who have a strong tradition of naming children after the grandparents but want to avoid having a kid who shares a name with numerous cousins. Or they merge their own names - I know a
Janine who married a
Rudolf and had a daughter Runine.
I don't know if Ms
Theron was named after a
Charles and an Elize, or if her parents just followed the merger tradition because they liked the sound of it.