Write what you do, not what you wish you did
Aspirational drafting creates the finding it was meant to prevent.
The most common defect in a policy library is not vagueness but ambition. Documents are drafted describing an ideal process, with timeframes and steps that nobody has costed against the resources available, because at the drafting stage there is no cost to promising more. The document is approved, filed, and becomes the standard against which the organisation is measured.
The exposure is straightforward. An assessor, an insurer or a court reads the policy, compares it to what happened, and finds a gap. That gap is entirely self-created: had the document described the actual practice, which was perfectly defensible, there would be no finding at all. Organisations routinely fail against their own inflated standard while operating reasonably.
The corrective is to draft from observation rather than intention. Find out what actually happens, including the exceptions and the timeframes that are really achieved, and write that. Where the actual practice is genuinely inadequate, that is a separate problem requiring resources, and writing a better document does not solve it, it only conceals it until something goes wrong.
Where an improvement is intended, the honest form is to state the current practice and record the improvement as a dated commitment elsewhere. That way the document remains true, and the intention is captured somewhere it can be tracked rather than being asserted as already achieved.
There is a variant of aspirational drafting that is harder to spot, which is copying a clause from a better resourced organisation. The clause is well written and describes a control that organisation can afford, and adopting it commits you to the same standard with a fraction of the capacity. Borrowed text should be read as a promise being made rather than as a form of words, and most of what circulates between organisations in this field is exactly that.