What response are you expecting from me? That it is ok to teach low ability to students without much subject knowledge because no-one will be able to notice? It is not my problem the type of schools you work in, but your pupils deserve someone with subject knowledge above and beyond "one week ahead". Putting on a martyr's expression and complaining about the difficulty of the situation is just making excuses. As for developing as a minority teacher, what is that supposed to mean?