Worldbuilding Exchange

In one of the fandoms I'm nominating, there are two historical characters who are never seen but who are referred to consistently as one unit, since they're twins. Would it be okay if I nominated them under a single character slot ("Character A & Character B (Fandom)")? Not because I think twins are a single character or anything, but because anyone requesting or offering either of them in this particular exchange would almost certainly be expecting to get both as a package deal.