Sentence Correction

Hello,

I did two questions recently and I got one of them wrong. However, when reading the answers, I got even more confused because I couldn't tell which thing are actually being compared. Here are the two questions.

Gliding, rather than actually flying, through the air, the flying squirrel is somewhat misnamed, like the flying fish; neither animal is actually capable of flight but early explorers based the animals' names on perceived, rather than actual, reality.
A. the flying squirrel is somewhat misnamed, like the flying fish
B. the flying squirrel is somewhat misnamed, like flying fish are
C. flying squirrels, like flying fish, is somewhat misnamed
D. flying squirrels and flying fish, both some what misnamed
E. the flying squirrel is somewhat misnamed, as is the flying fish

According to the answer, the correct answer for the above question is E. We need to use as because the animals themselves aren't being compared, what is the being compared is the action.

One of the duties of the Security and Exchange Commission is to guarantee that individual or small investors have the same information about the financial health of a company as do the large, institutional investors.
A. as do the large, institutional investors.
B. as does the large, institutional investors.
C. like the large, institutional investors have
D. in addition to the large, institutional investors.
E. as the large, institutional investors.

The correct answer for this question is E. The answer says the comparison is made between the types of investors and the do in Choice A is added incorrectly. This explanation seems contradiction to the other question previously I listed. To me, both questions compares the action(because "individual or small investors have..." and "the flying fish is somewhat..."), not the noun.

Please help!!

Could you tell me why the second questions tells me that the type of investors are being compared.