Happy to report that the standard unit I ordered from Batch 3 arrived yesterday and I had zero issues connecting it into my existing Full + Standard ones that were from batch #2. I did have an old USB 2 hub at the ready in case it was needed, however it was not. I hooked up the additional standard unit to one of the full unit's USB3 ports and it was immediately added to the party when I powered everything back up.

Thanks for a great job Team FutureBit!