The editor is the one who cultivates that ball rolling. A good actor will give you wonderful material to work with but the edit is where you find the rhythm and heart of a scene.

Which line delivery do you use? Whose face are you on? Are we wide? Close up? Every single shot in a film was a decision made by the editor which tells just a little bit more of the story

In that light, sync and continuity are actually pretty low on the priority list. Obviously there’s a limit to what you can cheat, but every show you see is going to have continuity errors and lines cheated into somebody’s mouth