Systems and methods are disclosed for using one or more gateway systems for integrating multiple load control systems running multiple versions of software such that the load control systems may appear to a user and be controlled by the user as a unified load control system. Gateways that manage or have managed the same resource may be organized into a Gateway Group. Gateway Groups names may be used for prefix attachment to facilitate routing. For example, a Composite Gateway may receive a request associated with a resource from a user. The Composite Gateway may determine which Gateway actively manages that resource and/or is the Gateway is a member of a Gateway Group. The composite Gateway may then apply one or more policies to facilitate the request. For example, if the Composite Gateway receives an information request, it may apply an authorization policy, a routing policy, and/or an aggregation policy.