Yes, naturally 33 > 1, so you might expect 33 times as many failures of individual components.

But your analogy between arrays of rocket engines and disks is apt, because both have redundancy to survive the failure of individual components.

For example, in the high-altitude flight test of the Starship prototype in May 2021, three of the 33 Raptor engines powering the first stage failed shortly after liftoff. The vehicle still managed to continue flying, reaching an altitude of 40 kilometers before failing due to a variety of causes.

> People genuinely don’t understand how statistics work

Indeed.

If an individual disk has MTBF of 2 million hours, the probability of it failing in the first year is 0.437%.

But put 33 of those disks in a RAID 6 array, which can tolerate 1 or 2 failures without replacement, and the probability of the entire array failing in the first year drops by a factor of ten to 0.0413%.

The statistics say the array is even more reliable than a single component by itself.