They have 20 auditing stations.
If they man all the stations, 24 hours a day, 7 days a week, each station needs to audit one ballot every 30 seconds or so.
They're not moving nearly that fast. (And they're not always using all the stations.)
Will they speed up as they get better at it?
For the first actual audit, I would say go the full monty and find it all. Ever trick and number so in WI, MI, GA, PA they can look for the same moves and make the margin. The dominos topple with the right pressure