The same way filebot and any other tool does - the file needs to have some label, either an absolute episode number or a season + episode number. I'm not aware of any tool that is able to look at the contents of the video to figure out which episode it is visually without any information from the filename - but I'd be happy to be proven wrong because I would be impressed.
Sonarr/radarr does analyze the content somewhat but that's just for gathering resolution, codec, HDR, audio languages, and subtitle information, which can all be added to the filename format for inclusion during renaming.
To add to the other reply, client isolation is about controlling whether an ap, switch, or router willingly sends traffic between clients. Because of that, it doesn't kick in if you listen to packets over the air before they've been received by an AP. For that kind of security you need a wifi specific security measure - which I think "enhanced open" is what you'd be interested in. It allows you to have an open passwordless wifi but it generates temporary encryption keys for each connected client, then the rest is as if it was using WPA, so that you don't need to enter a password but your traffic gets encrypted and protected from anyone else listening in on the WiFi.
If you combine both then you should have a network where each device is isolated both over the air and from a routing perspective so that each device only sees an Internet connection and no other devices.