I’m not sure what all English subs you have. I can only assume they are a combination of forced subs, regular subs, sdh subs, commentary subs, etc… If this it the case then the choice is yours as to whether you want them. I myself remove the sdh subs and commentary subs altogether cause I don’t want commentary of the movie or some text showing (MUSIC PLAYING ON RADIO), or (TREES BLOWING IN THE WIND), or (BELLS RINGING), or (SCOFFS), or (ENGINE SPUTTERING)
This might interest you. Read the first section carefully as it is directly responsible for displaying FORCED subtitles. https://support.plex.tv/hc/en-us/articles/200471113-Configuring-Subtitle-Support
Related Page: Account Audio/Subtitle Language Settings
https://support.plex.tv/hc/en-us/articles/204985278
Also, @OttoKerner talks more about it here and how to properly configure Plex subtitle support.
If you have a section in the movie where they are speaking in a different language, like Russian, for example, your forced subtitles will be displayed.
