Modern logistics systems aim to leverage digital technologies and may integrate autonomous components to increase efficiency and flexibility. In so-called mixed-fleet systems human workers, manually operated machines, and autonomous machines collaboratively work towards a common goal. The subsystems are loosely coupled and can be reconfigured flexibly, leading to a change in behavior. Addressing this behavior requires flexible architectures for model-driven systems engineering. Service-oriented architectures help focus on the expected behavior, independent of the involved actors. Additionally, event-based communication mechanisms can describe expected interactions between subsystems. This paper explores the use of SysML~v2 for modeling a service-oriented architecture of mixed-fleet systems. Based on an available set of requirements, suitable SysML~v2 modeling elements are identified that can describe services, events, and service choreographies. We use the described concepts to create a SysML~v2 model of a mixed-fleet harbor logistics use case. Based on this model, we demonstrate how business processes can be composed from reusable service and how requirements and verification can be integrated to ensure correctness of behavior. The results show that SysML v2 fulfills key modeling requirements for service-oriented architectures, separating service definitions, actors and verification. Reusable modeling patterns were applied to support scalability and traceability across actors and services withn the model. Furthermore, domain-specific constraints and requirements were composed into modeling elements using formal mechanisms to ensure that they are not only documented but actively connected to the model.