The 9.3x62 was created in 1905. It had decade in which to gain a secure foothold in German Southwest and East Africa before WWI. The 7x64, on the other hand, was created in by Wilhelm Brenneke in 1917. The First World War ended in November 1918 and resulted in the loss of the German African colonies to British control. Hence, the demand for a German light plains game rifle never materialized. The 7x64 and it's rimmed counterpart, the 7x65R, did go on to great and continuing popularity on the Continent of Europe.
9.3x57 was a bit of an odd duck. With the creation of the x62, the x57 had relatively little utility in Africa. As noted above, for some reason it did catch on in Scandinavia. Where the big, slow, heavy for caliber bullet was effective on the Scandinavian "moose."