I say: Contrary to what you said all the books agree on all the topics except a couple of them.
1. Actually, to be fair, that's what I did say, although I accept that perhaps my wording was a little ambiguous and the meaning was implied rather than explicit. I apologise for not being clearer. Fundamentally, most texts agree on a the basic tenets of the language, but there are enough gaps or controversial areas of disagreement (particularly when it comes to usage) to cause significant headaches; especially at a more advanced level of study.
Now the picture is clearer. We are saying the same thing.
2. I do not know wish to question whether the British Council teachers are authorities on English because although the minimum specified qualification for working as a BC teacher, according to you, is a CELTA, they should have other English qualifications to be selected as a teacher. I think we should respect them for having a vast knowledge of English. Otherwise, they wouldn't be answering questions from the members of the public. When I refer to BC teachers, I was actually referring to the ones selected to answer questions from public members.
I think you should close this chapter and proceed to more meaningful discussions on other subjects.