From what I can tell, all 3 of those are using the same translation; the different titles are down to different publishers.
According to ISFDb both You Shall Know Them and Borderline were translated by Rita Barisse. It appears to be a case where the same book was published with different titles in the U.S. market (You Shall Know Them: Little, Brown and Company) and the U.K. market (Borderline: Macmillan and Co.).
As for The Murder of the Missing Link, the linked review has this to say:
The ridiculous title conceals Vercors' "You Shall Know Them," and has the one beneficial result of giving it a mystery classification, and hence a lower price than SF.
This edition has "(Original title: YOU SHALL KNOW THEM") on the cover:
