I note that when Decca re-issued this album as A-449, the hyphens between the composer names on Decca 3484B were eliminated, making the composers a single entity named Audrey Robinson Archer. The only other Internet source I could find supports the position that that all the names belong to one lady.
Do you know if your copy of 3484 is original to the album, 78Ron? It is the only disc of the four that does not have the album number and album side numbers on it, which suggests to me that it may have replaced a broken original.
I am guessing that all of these sides were also marketed singly, then gathered into an album as an afterthought, but I don't currently have any other examples with the same label format as your 3484 to document that. I would think, though, that if the discs were made exclusively for the album, they would all have the same kind of label and they most likely would have been given consecutive catalog numbers, as well.