讨论一下, 不是很确切.

so as to的正确使用方法是前面只有一个主谓结构,因此在这种情况下其主语也肯定就是主句主语了. 在有两个人名出现的时候, 这种结构本身并不保证谁是逻辑主语.

比如下面一题,也是OG上的,在论述 so as to 的错误原因时都是说 fails to specify who is the people executing that action, 但并没有说A错误的原因是因为让人误解为"employers"是动作的执行者. 171也没有说是谁,而只是说没有明确是谁.

67. Congress is debating a bill requiring certain employers provide workers with unpaid leave so as to care for sick or newbom children.
A. provide workers with unpaid leave so as to
B. to provide workers with unpaid leave so as to
C. provide workers with unpaid leave in order that they
D. to provide workers with unpaid leave so that they can
E. provide workers with unpaid leave and
Choices A, C, and E are ungrammatical because, in this context, requiring ... employers must be followed by an infinitive. These options display additional faults: in A, so as to fails to specify that the workers receiving the leave will be the people caring for the infants and children; in order that they, as used in C, is imprecise and unidiomatic; and E says that the bill being debated would require the employers themselves to care for the children. Choice B offers the correct infinitive, to provide, but contains the faulty so as to. Choice D is best.