Although some sites do dislike 'thread resuscitation' , it has it's benefits in bringing past relevant discussion back into the topic.
As an adult beginner I don't know enough about the differences between the 3 or 4 (or more?) different awarding / examining bodies , but as someone who has taught in other activities and vocational ( for the workplace, rather the meaning attached in relation to dance) training I can understand, appreciate and sympathise with the teacher who does not want students confused by the differences in expectations between different awarding bodies or where other teachers are teaching poorly. I think anyone who has ever taught or trained , will have had experience of havign to dismantle someone's techniques and rebuild it because of past poor training they recieved especially in the case of somethign which relies on psychomotor skills and muslce memory ... also those forced to write in a particular style of script at junior school will find it is nigh on impossible to totally eliminate aspects of that style ...