Can I put both old drives back in and have everything work?

I have an EX2 running the latest firmware.

I had 2x 2TB drives in it for a while in RAID1. I shut the unit down and removed the drives.
I installed 2 new 8TB drives, configured a RAID0 and copied data back to that from a temporary external I had borrowed to backup the 2TB drives. I somehow missed a folder when I was copying stuff.

I don’t know which one of the 2TB drives was “Drive 1” and which was “Drive 2”.

Can I pull the new drives, swap back in the old drives, and pull some data off them without losing data on the 8TB drives or risking destroying data on the 2tb drives else by placing them in the wrong bay within the enclosure? Thanks!

You should follow the below mentioned links to safely swapping your hard drives without risking any data stored on your hard drives.

For RAID Roaming, You can go through the link mentioned below:

https://support.wdc.com/knowledgebase/answer.aspx?ID=17087