Re: 30,000 managers in 187,000 staff?
Over time a few jaded managers explained some common practices around management during layoffs ....
The upper levels of management are typically reluctant to lay off managers within their own chain, because that would in turn diminish their own (perceived) importance. Especially if they were to eliminate an entire layer between themselves and the trenches. Losing people here and there doesn't change their own org chart "status".
However, they're only too happy to do it to other management branches. And that's where the ugly politics and ladder climbing, nepotism, favoritism, etc. plays out.
So e.g., they explained, if you ever see an entire group culled, including the manager, that person had fallen out of favor for whatever reason, and the individual contributor employees were merely cannon fodder. It was possible, though not common, that some technology or industry turn had rendered the group's mission obsolete, and therefore the group cut could be legitimate; but usually before that happened, especially if the manager was politically popular, there would be a re-org to shuffle the manager out of harm's way for the upcoming layoffs.
Commenting on the trend towards smaller numbers of direct reports, cynical managers explained that group size doesn't really matter anymore. The more important thing is management tree depth, presumably because that's what everyone sees on the org chart. The more layers / levels you have, the bigger wheel you are. Or so the theory goes. And if you're managing only other managers, then you should be a director (or at least have a "senior" in your title), and on up and so on for directors, VP's, GM's, presidents, and executives.
Too cynical? I dunno. But it usually feels like management is less affected (even by proportion or percentage) by layoffs than the rank and file.