既然overall和as a whole放在一起比较,那就把重点放在overall作为副词的用法上.
overall adv (1)全部地,总共
The fish measures 1.7 meters overall.那条鱼全长为1.7米.
(2)(句子副词）一般地,总体上
Overall, prices are still rising. 总体上来说,价格仍在上涨.
as a whole 整个来看（用于表示所有部分都已经考虑）
This rule does not only apply to seniors, but to the school as a whole. 这条规
则不仅适用于高年级学生,也适用于全校.
我想这几个例句回答了你的问题吧?Good Luck!