There is no ranking system. Emory and Case have been around since '69, so as far as being "more recognized" they have obviously produced more AAs than anyone else. This being said (like my last post) that doesn’t mean that they are better-although Case would like to think so-they've just been around longer.
Besides, being around longer or "famous" doesn’t mean anything. Emory had a tremendous program director who left to go to South's program. Does that mean that Emory is bad now? No, but any program has potential to be if someone mucks it up. Does that mean that South has a good program now, because they got Emory’s old director? Probably. It’s all relative if you think about it. Plus, there are WAY too many critics of this profession. A good school like Emory isn’t going to allow someone to muck up their program and school that has been producing good AAs for 40 years.