Yes, he'd shave off 3 weeks out of his 5 months cycle. That's pretty good to me.Then you should maybe take some time to think it through?
If he had the best coders and they'd finish the day he'd finish the art, all you'd ever save are those 3 weeks. Once. After that we'd be on this same schedule again.
And I kind of refuse to believe that some people can go this nuts about 2 to 3 weeks.