> X is relative to a distribution on the questions we ask when we aren’t dealing with Encyclopedia Eric but with an LLM.

Assuming I understand what you mean here correctly, this should be the case for both LLMs and Encyclopedia Eric - there are topics Eric knows by heart (or thinks they know); there are specific phrases seared into his mind through sheer exposure during his life prior to becoming a living Encyclopedia. There are words he's used to, and exact synonyms he barely recognizes. All that means your chance of getting correct answer to your query depends, in complex and unknown to you way, on how you state it.