Yes it’s a real effect. I’ve just hardcoded offsets on various jobs:

  * * * * * sleep 17 && …

That way I still maintain a per-job 60-second cadence consistently (which random would not), but don’t do it right on the top of the minute.

That's interesting as it is also visible with a crontab -l so that new scripts can avoid using the same second. However, if you have a farm of machines with the same hardcoded value, they will all still stampede at the same time just not at the top of the minute. By allowing a random value, their start times are slightly offset with in the minute. Is the precise 60s consistent interval really that critical or just that each machine checks once per minute-ish?

Systemd timers do this natively btw, no need to hardcode And imho are also friendlier.