The practical signal
Staff leaves, phones change and keys are swapped. A contact list that is not updated after delivery becomes increasingly unreliable.
The quality of reporting from the command center depends a great deal on the current contacts who know what they should do.

Staff leaves, phones change and keys are swapped. A contact list that is not updated after delivery becomes increasingly unreliable.
Check the names, numbers, availability, order, and authority of each contact person. Determine who takes over the role during vacation, night, or illness.
Assign one owner to the list and use a controlled change route with confirmation. Avoid isolated changes through unclear channels that do not land in the protocol.
Conduct a contact test or confirmation round and have each keyholder share the current action plan. Note the date of the last review.
Enough for accessibility, without an unclear endless call list.
That depends on the action plan and the desired physical follow-up.