You cannot call external classes, or data groups in general, as object references in the config.
Just curious, but are all of the nodes listening on the same port? If so why not create a single pool and apply to all of the virtual servers.
You could potentially automate the creation of each individual pool given a list of nodes. This wouldn't solve the config file size issue, but it would make your life a lot easier. As for storing the entire application in a class for easy reproduction, that too could be automated via TMSH or an iApp.