Firstly, that process did not happen in a short time frame. And in many cases we are wanting records about the earlier form of the church and even if it existed at all (Llandaff). And it was in line with reforms begun under Edward the Confessor. Secondly, things varied from region to region quite markedly, as did the outcomes. It's easy to overstate the Norman evil. The reality, as with most history, is far less black and white.