> That in turn was followed by a small exodus of many of the better engineers (since that's who is able to leave easily when things go south.)

That is such an obvious outcome. When it seems layoff/low-morale seems to be coming, people who will leave for new jobs on their own are usually ones with the initiative, right skillset, youth, good with people, etc, which is why they can get a new job with ease. And these are the very people a company wants to hold on to. So the other option to achieve attrition rate is to have lay offs. But of course that is not good for reputation of the company.

> Five years later that company is now two CIOs removed from the original attrition warrior who left presumably to help the attrition rate even.

I have a suspicion the CIO was specifically brought in by higher ups to force higher attrition rate.