I have been thinking about this, and I wonder whether the 'stress' vs 'considerations of knock on effect on the rest of the cohort' is just another example of good senior management making different decisions in different contexts?
I mean, for example: high pressure all girls' schools have, traditionally, been [against the general population] high risk for eating disorders, so such schools in the modern era, have good leadership who take this into account in everything that they do. Schools in very challenging circumstances in particular areas may [again against the general population] have a high proportion of those who are vulnerably housed, and good leadership in those schools will take this into account in everything that they do. At a less 'obvious' level, some selective schools may have historically had a higher level of stress-related mental illness and its different manifestations than the general population, and therefore good senior leadership builds this into all the decisions that they make. Non-selective schools may have a lower rate of stress-related mental illness, but they may have a higher level of pupils who show challenging behaviours, so a good senior leadership team builds this into everything that they do.
Each specific school, of whatever type, builds these 'specific historical experiences', and what it knows about its current students into all its decisions, taking into account the limitations of resources every school faces.
The fact that different decisions are reached by different institutions, even of exactly the same type, surely represents GOOD, reactive, thinking management, not poor management? The fact that we can all sit here and type about our different local experiences and each see these as 'right for the circumstances our local schools find themselves in' just demonstrates that there ARE different good answers, surely? It doesn't mean that a school is saving face / protecting its results / wishing harm on its pupils / is poorly managed, just that all educational decisions in fact all critical decisions involving groups of real people, tend to have a finely balanced 'on the one hand / on the other hand' debate, which can easily be tipped one way or another by relatively small differences.