Thanks for this. I activated the mod using Jon Scone's Generic Mod Enabler available below, rather than overwriting stock files. One advantage of JSGME is that you just deactivate the mod(s) when game patches are installed and then re-enable them after updating and taking a new snapshot of the stock game.JSGME
After installing JSGME into the AJE directory and creating the snapshot of stock AJE as per instruction I just renamed the mods' AJE folder to RSR and dropped it into the newly created MODS folder. Once activated the mod seems to work as intended (and in doing so makes fighting the Cantabarians that much more difficult; cool!).
I use JSGME exclusively to mod WW1G but this is my first crack at installing mods with it in mainstream AGEOD games.