Tim:
Briefly looking at RAID information, there are things that should be unique, and there are some things that can be duplicated (not so sure that they should be, though). Drive IDs would need to be unique for anything that uses IDs to differentiate one drive from other. There's partition and volume IDs that are used for different purposes.
Peter Boy:
I agree. But it’s hard not to use UIEDs and to ignore misconfigured UUIDs. Many Fedora tools use UUID by default, e.g. Cockpit and - if I remember correctly - dbus. Therefore, cloning a disc often ends up in more work than cloning saves.
Since my experience with RAID is minimal (using a motherboard with built-in hardware RAID that could not be shut-off on the drive ports I had to use), I assume that if a mirror drive dies, you swap it, and let the RAID do its own magic to incorporate the replacement drive into the system, it handles filling up the new drive with partitions and data from the other drive without cloning IDs.