Finances are challenging. Our first goal is to make sure the finance view in-game makes sense, so that you don't have the "mystery numbers" that versions in the past have had (ie. having absolutely no idea why you did not have the money to do a certain move). I think 16 will solve some of those flaws.
But otherwise, yes, we likely should spend some effort documenting the financial model. I don't like doing it, but I do agree that it should be done.