Not everyone needs access to the same information. An owner needs oversight. A manager needs team activity. A staff member needs what is relevant to the job in front of them.
The shape below is an example, not a fixed template. Permissions are defined around how your organization actually works.
One system, one contact record. Open anything below and keep going from there.
A well-organized team workspace balances collaboration with appropriate access. The structure is yours to define, and it changes as responsibilities change.