If you do want different people working on different parts of the game (and they're all, say, creating text), and assuming we're speaking about Quest here (
), Quest supports libraries. So you can split the code up into separate library files and have them simply be included in your main game file. There are some difficulties (e.g. you can't directly reference an object in the main game file as another object's parent), but it might be doable.
It's hard to be more specific without knowing more specifics.