The correct configuration is a Service Crew. A Service Crew models multiple technicians who need to work as one coordinated schedulable unit. The crew can combine specialized skills and is represented in scheduling by a Crew-type Service Resource.
Salesforce favors reusable resource metadata over one-off record manipulation. When resource qualifications and availability are modeled correctly, the same information can support candidate selection, optimization, dispatching, reporting, and mobile execution without duplicating logic on individual jobs.
The alternatives address different parts of the Field Service model. Required Skills alone do not create a two-person team, and separate crews or separate independent appointments are unnecessary when the resources must perform the same job together.
This keeps the workforce model reusable across scheduling, dispatching, mobile execution, and reporting and avoids encoding resource logic in individual work records.
This approach keeps the implementation aligned with the standard Field Service data model and avoids unnecessary customization. Study Guide reference: Managing Resources — Service Crews; Crew Members; multi-technician work.