If the main problem is unclear & changing requirements, having 2 different implementations of a system that attempt to implement the vague / changing / missing requirements doesn't seem immediately helpful -- they'll almost certainly disagree, and then you can force one to match the other or so on, and have two implementations of some arbitrary thing.
But none of this "implementing stuff" is making progress to solving the issue of unclear / changing / vague / missing requirements.
But none of this "implementing stuff" is making progress to solving the issue of unclear / changing / vague / missing requirements.