umm no i think you find the animation of the mouth is fitted into place AFTER the voice recording has been done.

and who says? i do. i study and analyse them and have even had a few goes at writing them. go read a play, you will see how timing is hardly ever incorperated into a script, if it is its to do with a particular movement and neevr to do with a routine scene (for example there may be an indication to 'pause' after an important speech, but there will never be an order to speak form xx:xx to yy:yy)..

but like you said you cant compare them (perhaps not, ive only ever read the script to animated films) but like i said at first the voice acting is done first, then matched with the animation.

also the timing is the job of the director, not the script writer, often the writer will have no control whatsoever over anything you see on screen, just the story and dialouge.