I can totally understand what you’re saying here. I happen to edit the English subtitles of a Thai lakorn as the CE. There had been a couple of sentences that needed to be edited so they could make sense in English. However, I was afraid that my editing would cause a change in the meaning of the sentence. That’s why I asked the TE to check those subtitles again and explain to me what exactly she wanted to convey.
Every language has its idioms and phrases that don’t exist in other languages. Changing those sentences can lead to mistranslation.
In conclusion, I believe that as an English editor (GE or CE) when you come across a subtitle that confuses you, the best thing you can do is open the history under the segment to see how the subtitle came to be like that. If you still can’t understand completely, you should ask the TE. Nobody will criticize you if you make some questions.