THANKS for all your help with this!
No worries, happy to help.
Well this looks all ok to me.
There might be issues with the D+B emergency mode not being able to untar or something else.
Danboid had issues but somehow managed to get it working.
If it is not too much to ask, I would recommend to use the SD card guide I posted earlier.
This will give you a backup system and a good start to install arch on the microdrive while running from SD card.
This way you can use the full 6GB (and swap) because your backup system sits on an SD card. (5.8 GB + 0.2 GB swap)
Let me know if you have issues with the how to.
Your cards are very likely supported, would be good to test once you got Arch going.
You can test your cards once you got Arch on a SD card, to make sure, before proceeding.
Cheers and thanks for trying