For stuff like movies I simply use replication as my backup.
Since I share media with fruends/family, I act as the central repository and replicate to them on a schedule (Mom on Monday, Friend 1 on Tuesday, etc), so I have a few days to catch an error. It’s not perfect but I check those replication logs weekly.
I also have 2 local replicas of media, so I’m pretty safe.



The only concern I see here is the external drive. My experience has been that powered off drives fail more often than constantly-on drives. So my external drives are always powered on, I just run a replication script to them on a schedule.
But you do have good coverage, so that’s a small risk.