My Book Duo - RAID vs JBOD with Rsync?

Hi all,
My question might be confusing so please try to understand the specific need

I have a backup and archiving system which work well.
I am a bit paranoid, so I bought in addition My Book Duo which I want to connect to a computer for local backup daily (but manually)
RAID isn’t a backup, but in this case if I copy data from my PC to the My Book, then it will sync to the other disks (not sure if at real time or not)

The other option is to manually copy from one disk to another (rsync or what ever)

Which way would be more reliable in terms of data loss? (Ignore the fact of power loss please)

Thank you!

Hello,

Please be informed that the RAID system is more reliable in terms of data reliability than JBOD as RAID is a system in which a group of hard drives are joined to the network to assure high reliability of data

Thank you. It will be great if you can extend your answer a bit.
In terms of data integrity, RAID mirror mechanism is more reliable than rsync or any copying??

If rsync fail, I can see what file or at what stage. With RAID I don’t really have visibility hence my question. So it will be great if you can comment on that