No, they would get a shit ton of ballots for "unlikely registered voters" especially if they are deceased or moved. Those are probably 100% solid.

The rest of the unlikely voters that still live in the county, they have the info for all of them and they simply make sure the person didn't vote, take the already filled out ballot and drop it in the "fake vote pile" and send them in at 4 am after voting is over. That's why they want the extended time for mail in votes with no postmarks. Gives them more time to add more fake votes to the pile.