> Luckily, it was during the warm up and not 2 weeks later after being active.

While there's always luck involved, dying during warmup and not two weeks later is the expected experience for drives that defective.

So what happened to you wasn't that you made a backup and then it failed so fast you couldn't use it. It's relevant to what I was saying is unlikely, but it's not an example of it.

Plus at zero weeks or even two weeks you have the previous backup system around. If you have a big simultaneous failure 6 months out, that's a scary situation, but that's much rarer.