These two scenarios are fully supported by Maintenance Plans, which allow creating recurring work orders and service appointments based on various criteria. References:https://help.salesforce.com/s/articleView?
id=sf.fs_maintenance_plans_overview.htm&type=5

Explanation
Service Appointments are records that track the date, time, duration, and assigned resource for a work order or work order line item[117]. Creating a new Service Appointment for each site visit would allow Universal Containers to track when Technicians need to visit a customer site multiple times to resolve an issue by creating different service appointments for the same work order and capturing notes and status updates for each service appointment. Creating a new Child Work Order for each site visit would create unnecessary records and complexity. Child Work Orders are work orders that are related to another work order as part of a hierarchy[118]. Creating a new Product Consumed for each site visit would not track the site visits. Products Consumed are records that track the products or parts that are used or installed during a service appointment[119]. Creating a new Work Order Line Item for each site visit would not track the site visits.
Work Order Line Items are records that track specific tasks or products related to a work order[120].
References: https://help.salesforce.com/s/articleView?id=sf.fs_service_appointments.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.fs_work_orders.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.fs_products_consumed_overview.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.fs_work_order_line_items.htm&type=5

Explanation
Capacity-Based Service Resources are service resources that have a limited number of hours available for work per day or week[150]. Setting the Contractor Manager as a Capacity-Based Service Resource would allow Universal Containers to outsource 100 hours of weekly maintenance to an external Contractor by setting up criteria such as capacity hours per week equals 100 and capacity type equals weekly[151]. Creating the individual Technicians as Service Crew Members would not work because Service Crew Members are service resources that belong to a crew and share the same service appointments[152]. Setting the individual Technicians as Capacity-Based Service Resources would not work because Universal Containers does not have visibility into the individual external technicians. Creating the Contractor Manager as a Crew Service Resource would not work because Crew Service Resources are service resources that act as leaders or managers of a crew and can assign crew members to service appointments[153]. References:
https://help.salesforce.com/s/articleView?id=sf.fs_service_resources_capacity_based.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.fs_service_resources_capacity_based_create_edit.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.fs_service_crews_overview.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.fs_service_crews_create_edit_delete.htm&type=5