It's a process problem. If an engineer shouldn't be able to run a SQL delete query without a where clause, then there should be processes, procedures, or tooling in place to prevent that.
If you're genuinely asking why you shouldn't publicly incriminate yourself on the internet that might explain why you have interacted with so many subpar lawyers.
I've run into so many issues with Nomad that it really doesn't make sense to compare the two. Many are well documented in Github issues and occur when utilizing other Hashicorp products.
Any organization that requires nanosecond precision uses PTP. In my experience this usually includes financial exchanges that want to measure latency in trade routing.
Can you provide the model of the GPS hardware? I work in the same industry and have set up multiple NTP / PTP timer servers that have never failed to account for leap seconds. It's almost always the downstream software that crashes. See the 2012 leap second insertion as an example.