OG 187, 想不通

187. In one of the bloodiest battles of the Civil War, fought at Sharpsburg, Maryland, on September 17, 1862, four times as many Americans were killed as would later be killed on the beaches of Normandy during D-Day.

(A)  Americans were killed as

(B)  Americans were killed than

(C)  Americans were killed than those who

(D)  more Americans were killed as there

(E)   more Americans were killed as those who

答案是A，但是我觉得应该是 americans were killed as those who, 难道省略those who 是可以的吗？ 我怎么就是读不顺呢。。。。

哪位能解释一下呢？非常感谢

还原：

Americans were killed(....) four times as many as(Americans)would later be killed on the beaches of Normandy during D-Day.

as..as前后的句子结构与意思都对称。

比较结构中，如果主语相同则省略