Comment by hammock

>I was quite surprised to see that after writing the script they had stand-in actors do the entire script, which they then did animatics (storyboards times to the recorded audio) to, after which they edited the story. Only then did final actors record. Then redo animatics and editing before doing final animation

I have no experience in animation, however that process is not unlike the common process in music production: a song is written, a demo is cut by the songwriter, a "scratch track" is cut by the chosen lead vocalist and an instrument or two, then the arrangement is recorded by the band (to the scratch track), then final vocals are cut to the band's backing track, and often after that tweaks to the accompaniment are still made.