Abstract-Virtual evaluation of complex command and control concepts demands the use of heterogeneous simulation environments. Development challenges include how to integrate multiple simulation platforms with varying semantics and how to integrate simulation models and the complex interactions between them. While existing simulation frameworks may provide many of the required services needed to coordinate among multiple simulation platforms, they lack an overarching integration approach that connects and relates the semantics of heterogeneous domain models and their interactions. This paper outlines some of the challenges encountered in developing a command and control simulation environment and discusses our use of the GME meta-modeling tool-suite to create a model-based integration approach that allows for rapid synthesis of complex HLA-based simulation environments.