I am so lost. I am not sure what the alarms are, and why it was important to fool the ‘audience’ with fake copies so the real ones would go unnoticed. What is so special about them? And how would a pickpocket know who had one and who didn’t?

Oh! thanks for edits! Now I get what the alarms are all about. Ralph is sending the pickpockets in like lambs to the slaughter! He’s taking a real chance here.