And even if you accept that some shuffling occurs in the mail system, it's not nearly enough to homogenize the entire mail-in ballot intake.
Certain sorting centers (i.e. the first 3 digits of a collection of ZIP codes) are still going to have drastically different demographics than others. So as trays of mail arrive, and are stacked up in the tabulation centers, they're likely to stay clumped together.
It is completely unsurprising that a very large batch of mail-in ballots, arriving in one transport, are going to show a high ratio of D/R votes compared to other batches of mail-in votes. Knowing where the voters in each batch live will explain the differences.
Certain sorting centers (i.e. the first 3 digits of a collection of ZIP codes) are still going to have drastically different demographics than others. So as trays of mail arrive, and are stacked up in the tabulation centers, they're likely to stay clumped together.
It is completely unsurprising that a very large batch of mail-in ballots, arriving in one transport, are going to show a high ratio of D/R votes compared to other batches of mail-in votes. Knowing where the voters in each batch live will explain the differences.