grammar - "If you or somebody you know" vs "If somebody you know or you"

The following sentence makes sense:

• If you or somebody you know is an experienced such-and-such, please contact us.

However, reversing the subjects (and choosing "are" based on the proximity rule) makes it sound extremely awkward:

• If somebody you know or you are an experienced such-and-such, please contact us.

The is/are verb choice does not really matter, placing "somebody you know" first makes the sentence difficult to read and awkward to say. However, switching subjects in a compound subject doesn't always "ruin" the sentence, e.g.:

• If your dog or your cat is sick, call the vet.


• If your cat or your dog is sick, call the vet.

My question is: What is wrong with "If somebody you know or you"? Is this violating some grammatical rule? Why is this sentence so hard to parse? I know it doesn't "feel" right but I'd like to know why.