Your arguments really go to the credibility of the documents and can be used to question them as actual contemporaneous notes. In other words, use the sudden appearance of these notes that do not look like notes made at the time as proof that the other side is manufacturing false documents in its desperation to avoid liability for its conduct.
As long as the other side has someone sponsor the documents by claiming they were created at the time and placed in some other place, they will likely be admissible. However, often the play backfires on the forger and the judge or jury clearly see they made things up. Credibility is the battle that you want to win the most at trial. If the judge or jury believes the other side is willing to forge documents and perjure themselves, they will generally lose in all close calls on all of the other evidence as well.
Good luck to you.
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