Your requirements are not necessarily unreasonable, but I see an issue that should be raised.
Company policies, like acts and laws, have 3 distinct aspects. First is the creation of the policy (legislation). This should identify the specific objectives being met and associated requirements in support of the objectives.
Second is interpretation of the policy. Consider this the judicial review against other policies as well as against meeting the intended objectives. Interpretation should include action taken against those who violate policy.
Third, there is enforcement. This is simply identification of policy violation, either as written or as later interpreted, stopping the violation, and reporting the violator to appropriate group for action.
Most problems with IT policy come from IT assuming all 3 roles. Policy should be defined by business leadership. Yes, input comes from various sources, but they determine the policy objectives and non-technical requirements.Perhaps the business units should be tasked with interpretation. IT should handle enforcement of the policy.
The gain for business occurs with situations like the initial posting. The company policy that is preventing the consultant from havingaccess has specific objectives and requirements. The business unit that brought in the consultant is tasked with interpreting how the company policy applies. IT enforces the policy and interpretation.
If IT feels an interpretation defeats the objectives of the policy, these objections and their recommended changes should go back to the policy makers for consideration.