vivi vivi you did not understand my question here, we will need to discuss that in much more details…. In some movies the main language is English for example, but sometimes you have scenes left in the native language for a very good reason (for example Chinese in a Jackie Chan movie), in this case, we want to keep these scenes in the native language in order not to destroy the flow of the movie…. This case needs to be thought through and an option need to be there to give the option of what to do.
If not, then translator might just ruin the movie, the best example I can thing is a movie called The longest day 1962 which has at least 4 spoken languages and trust me you do not want to mess this one up….
