Costume Sharing at 20th Century Fox

I was watching the film "The Snows of Kilimanjaro" (1952) today, when I noticed actress Hildegard Knef wearing the exact same dress Marilyn Monroe wears in some very iconic photos. I know that Marilyn was under contract at 20th Century Fox, so I looked up the movie I was watching and sure enough, it was a Fox film. I found this quite interesting, since I'd never noticed two classic starlets wearing the same dress before. I figured they would have had their own very specific wardrobes, which I'm sure they did for the most part. Was it because Marilyn wasn't a superstar yet in 1952? Or was it because Hildegard was so unknown? Anyways, I looked up some other Fox actresses, and I found another double! A promo shot of Susan Hayward wearing the same costume that again, Marilyn Monroe wears. But this time from the film, "Bus Stop". Has anyone noticed any other doubles? If so, let me know!