@piscis
The purpose is childcare to allow key workers to work, it isn't about keeping the children or their parents any safer
Yes, but the safer it is, the better, because parents can keep working. If the bubble burst, that will have an impact on most of the parents, who will need to isolate. So having too many kids in one class is risky and ultimately will lead to keyworkers not being able to work at some point.
I am not saying there is an easy solution and I understand staffing issues but putting kids in bigger groups is really not ideal.
...the key phrase there that I look at is "the safer it is, the better, because parents can keep working"...
The only way the school can have smaller groups is if fewer children are sent in. Doubling up on producing remote learning materials (not live lessons) is the only area that school staffing can free up a member of staff to take physically present pupils.
In many cases if 10 pupils are off, or 100 pupils are off, one member of staff can produce remote learning material. However if the class size is normally 20 then with just 10 not attending class sizes have to rise whereas with 100 off there is the possibility of smaller class sizes. However, the Government brought in a legal obligation with regard to remote learning that makes it much harder to use that kind of economy of scale.
That also only works if you have a large enough school to have multiple teachers for each group/subject.