The fact that no-one has yet changed comes down more to manning (or the lack thereof)
Sorry to conterdict you but there's been 6 AEOps crossed over and passed(or soon to pass) the Shawbury course. I,ve not heard of any more coming this way and I,ve yet to hear of any loadies going the other way. Maybe it's due to location rather than job but I think the vast majority of ALM's could be re-trained to be AEOp's if they wish.
PS I am an AEOP I just can't spell that good!!