For my essay research I've been looking at 'The Art of Animation' by Don Bluth. Its been relatively helpful. There's a quote in there that Bluth uses which mirror's Phil's words.
'The story ideas and gags will be better after they are animated. This is absolutely NOT TRUE. Animation will only dress up your material. Good story material can be poorly animated and it will still play for the audience. Bad story can be superbly animated and it will never play. Your animation, no matter how wonderful, can never overcome a poorly written script.'
Also looked at a few interviews with Don Bluth about his animation.