I think I agree with you. That said, internal and external are a touch inadequate. Specifically, for a large enough system, internal consistency will look mor

I think I agree with you. That said, internal and external are a touch inadequate. Specifically, for a large enough system, internal consistency will look more like external from a smaller system's perspective. To that end, it is all about costs. If the cost of keeping consistent is not above the budget, do so.