I agree it's a problem and one that has been around for a while, the cadets at Tamworth in the 90's were pretty bad to, I know when doing a license conversion it is up to the instructor doing the flight review to asses the standard of english but I'm unsure of the rules as far as a student training here is concerned.
Don Pollack was running a aviation english course with his wife, he probably has all the information one would need to run the course. Ive lost contact with him over the years but the last I heard he was in mount beauty Victoria.