Don't really have the context, but I'd trust the expert that it will get done on the schedule they want. I'd say people on the outside of things often ask these kinds of questions due to lacking any context on production schedules. See: the last time your PM said "can't we just..."

He's also a small shop and perhaps they intentionally move slower. I suspect he doesn't need to urgently get paid for this.

Story writing is probably non linear in time it takes, and I imagine there's a fair amount of waterfall. E.g you can't schedule voice actors until the story and dialogue is done. Oh wait, the voice actors have other commitments so they'll be by in 3 months. Etc.