nasa,
Can't comment as to your unspecified examples of course but the fact remains that, if the homework, project management, and strategy is sound, and the assessment priority is assigned by CASA, there ought be no reason why an AOC cannot be processed in 5-6 months from scratch. I suggest that your examples will have relevant circumstances which account for the delays.
So far as the AOC is concerned, any such transfer as is being discussed in this thread will involve an issue of a fresh AOC ... I am not aware that there is any alternative to that.