You cannot define custom naming patterns in Plex.
Plex will always require
Movie Title (year) - optional stuff.ext
Where ‘Movie Title’ can be either the original or the localized title.
If you want to play it safe, go with
Localized Title (year) - [original title_quality].ext
Or you could resort to placing each movie into its own, individual subfolder.
That way, you can very likely leave the movie filename as-it-is. But the title of the folder must adhere to the above pattern.
The basic minimum for a folder name is Movie Title (year).
Filebot can help you to achieve that almost automatically, if you look into a custom renaming format string.
