> Also, keep in mind that I never said it would be a huge benefit at all- I only said that SOME compression was possible SOME of the time.
This is a common misconception. The pigeonhole principle here tells us that any scheme that ever achieves some compression also achieves some expansion. The only reason compression algorithms work at all is because they are more likely to compress than they are to expand, because we know something about the probability distribution of the plaintexts.
The pigeonhole argument treats compression as a black box with input and output, and makes no assumption about how the compression works.
Your idea—to only compress some inputs and not others—doesn't change the fact that your algorithm can be treated as if it is a black box with inputs and outputs. So the pigeonhole principle still applies. Many people before you have made this argument before, so we are very familiar with it, and very familiar with the reason why it is wrong.
FURTHERMORE, compression, by its very nature, works very poorly on data which is apparently uniformly distributed, as encrypted data is.
This is why you are wrong.