I think you have a few false premises. One of them being that Jagex bans manually. Jagex has stated that they've banned over 300k accs in one month previously. If they spent at least 1 minute per account they'd need over 5000 hours of work every month to review that many accounts and ban them. Most of the detection and flagging is already automated, Weath just has to press the button or run whatever program to ban most of them, I'd say a very small percentage of the accounts actually get reviewed.