To RAID or not to RAID

Hello Community!
I have been trying to decide on a home backup solution. We have multiple Macs and I would like to make sure they are all backed up wirelessly. I am trying to decide between these three solutions:

  1. Single External HDD to be used with Time Machine (cheapest option)
  2. Two external HDDs and set Time Machine to back up on both drives (medium cost option)
  3. Purchase a RAID WD solution, set to RAID 1, and back up using Time Machine (costlier option)

Since the data will still remain on the computers and the externals will serve as purely a backup, should I invest in solution 2 or 3?

Please share your thoughts! Thank you!

If you are keeping the data on the host computers and use your external drives as backups then I’d recommend option 2.