FragaGeddon

Thanks for the info. I ended up doing what I was doing before. Creating a share and using only one drive, instead of selecting like disk 1, disk 2, disk 3, etc.
And the too many devices error was I forgot that I was trying a different USB, that I was going to do a fresh install with. I didn't bother using a parity drive or a cache drive.
My files are backed up on external playbooks, so if one drive fails, I'll just replace it and put the files back on it.