You're talking about something different, I think. You're talking about the observers in the room, right? All those people do is watch the workers process ballots. They're not allowed to actually get involved.
I'm talking about having Republican and Democrat representatives, appointed by the party, who are actually responsible for validating signatures. Let the computer handle the bulk of them, but any signature that is questionable should go to the party reps for final evaluation. If they don't both approve, then the ballot gets flagged for a fraud investigation.