The plan sounds solid to me. Keeping a set of the camera card originals (in their original folder structure) somewhere to refer back to can be helpful for all kinds of reasons. What to do with them once the project is wrapped for the purposes of archiving is up for debate.
Renaming those files to something useful prior to the project getting underway (i.e., editing) should be fine, but doing so after things get started could wreak havoc. So now’s the time to agree on a renaming and overall organization structure, and from there, stay consistent.
Some things to keep in mind. A mirrored RAID isn’t a back-up in the truest sense. It’ll keep you rolling when one of the drives flatlines (in most scenarios), but a true redundant back-up means you’ve got two 10 TB RAIDS, where one is an incremental of the other, such as every hour, 6 hours, night, week, etc. Whatever your risk tolerance is. My general encouragement is to always by harddrives in pairs.
That can be helpful for a variety of reasons, such as deleting something by accident, and needing to go back in time to get it back. A mirrored RAID will delete it in real-time and you can’t get it back.
If the 10 TB RAID is just there to back up the 4TB drive, so that the 4TB is the editing disk, be sure to keep roughly 85% of free space on the 4TB drive. Pushing it past 85% will lend itself to slowdowns and possible file corruption.
And lastly, for the paranoid, none of these HDs sit in the same building at the same time for very long.
— Joby.