They are about 25 hours apart, which isn't very large I'll admit.

Thankfully, the serial numbers aren't too close to each other, so I'm hoping they aren't part of the same batch.

In my experience with enterprise SSDs (which yeah aren't the same but that's what I have to offer), SSDs with sequential serial numbers and identical on-times, in the same RAID array, can have wildly different actual endurance. Some storage servers I used to admin had SSDs lasting longer than 2 neighbor replacements from the same original box, and this happened at least twice.

I stopped being worried about on-times after that for SSDs. HDDs are still quite correlated (on the order of months) but if you're building the server you have to put the disks in it at some point.