it’s also worth noting that the documentation by fly does not create volumes in new zones when horizontally scaling as described here Horizontal Scaling · Fly Docs
Simply cloning the machine will create volumes in the same zone which seems to be causing some confusion. Which is why I needed to define these two steps separately in my solution
fly volumes create pg_data --app [APP-NAME] --region [REGION] --require-unique-zone --size [YOUR-SIZE]
fly machine clone [MACHINE] --attach-volume [VOLUME-ID] --region [REGION] --app [APP-ID]