Based on other videos I've seen here the TL;DR
Subs and Closed Captions serve different purposes. The latter is for accessibility/hard of hearing and meant to be a literal transcription of what is said in that language. The former is mostly meant for language translations. To aid in understanding.
Dubs have to roughly match mouth movements because the video is the same for all languages. I know this isn't true in every instance, but close enough.
Subs are translations from the original language, not from the dubbed audio.