First have the actual role and knowledge assessed. A process name does not justify duplicating preparation or claiming responsibilities the employee does not hold.
Define the evidence approach from the facts
Clarify the professional scope, supporting records and current official charges. Preparation should explain the actual capacity accurately rather than create competing job descriptions to cover every label. Settle the category question before commissioning work, rather than by commissioning both.
Hypothetical example: a tree inventory and vegetation-mapping specialist is asked to prepare a managerial description alongside a specialist one so that whichever fits can be used. Two descriptions of the same person doing the same job is not a hedge; it is a contradiction that has to be explained later, and it doubles the drafting cost for nothing. Pay instead for one short assessment of the actual duties and let that decide.
Ask the adviser what evidence each path would need, what it would cost, and which path the facts as described actually support, then ask what remains unresolved. Confirm current official charges when the step arrives rather than relying on an older figure, and keep the professional scope in writing so that the boundary between assessment, preparation and any later response to a request for further evidence is clear from the outset. Ask also who will draft the employer letter and who will review it, because a letter written by someone unfamiliar with the standard usually has to be rewritten and is then charged twice.