In the cases where this has been tried, the school becomes and has become better at teaching knowledge when those who control the teaching, school politicians and teachers, conform to the latest research results in pedagogy. This is what Birger Schlaug claims in Free Newspaper.
Among other things research says that homework reinforces class differences as not all parents have enough knowledge to help their children at home.
Then the total learning of knowledge is lower when the weak students are brought out to special educators. The strong don't get stronger, but the weak get weaker. Outstanding positive results have been found where the weak students were kept in the class and in addition special educators were brought into the class.
The school will thus be better if school politicians and teachers study and follow the research results.