Move AppleRaid stripe from USB to SATA

[digitalm3]

I bought 2 new larger disks to replace / upgrade a volume I have setup in El Cap. Since I don't have enough SATA ports to attach all of the old and new disks together I used a USB dock for the new disks, used diskutil via terminal to create the new appleRaid stripe then I proceeded to copy the data from the old volume to the new one. I then replaced the old disks with the new disks expecting OS X to see the new volume but the disks are coming up uninitialized and the volume is no where to be seen. Where did I go wrong, and is there anyway to reinitialize the new disks / array without losing the data?