That's about right. As an editor for a government contractor, I frequently refer to the GPO style manual (Government Printing Office). As a grad student, I used APA (American Psychological Association). And then individual projects frequently cobble together their own style guides based on the above and, often, Chicago. Documents need to be consistent within a project, ideally. But not really beyond that. Stuart
I tend to think that only recent teachers say Strunk and White is definitive. I wonder if these are the "teaching to the test" brand of teachers. It used to be only "Enthusiastically recommended" not "Law." What the heck is going on with the school system. English changes day by day and year by year. Once the Republicans are out of office, Literature as an art may come back in the US. This is all that "no child left behind" garbage which has unfortunately left most of the US population under the age of 20 as illiterates (but they know math very well). By the way, South Africa is now putting out the best writers (South America/ the Asian nations have always been great) They must have a great school system there.
No Child Left Behind has had an horrible impact on not only writing but on all fields addressed in the public education system. The idea was good, but the implementation was horribly wrong.