I see what you're saying. However, I'm partially with classics_chic on this one. I think that Bradley has her uses- she's a great summary for some elements of the Greece course, and I continue to find her useful for terminology for Rome, as I'm not so familiar with Latin. However, relying on her extensively can cause problems becaus, especially for such periods as the Persian Wars, she doesn't show a lot of depth and there are many important details that are lacking. From memory, the Battle of Artemisium is dismissed in something like 2 lines in Bradley, which I find incredibly problematic. She's fine as a back-up, but I do believe that you need to look well beyond her if you want to get good marks. There are plenty of books which are almost as easy to read which give a lot more detail, and are written by scholars of far greater distinction than Bradley (Bury for Greece, Scullard for Rome, there are plenty of others). Also there are plenty of online sources which are increasingly reliable (I never thought I'd say that!). If you look to Wikipedia, inaccuracies are edited out pretty quickly so you're relatively safe, and quite often universities (especially in the States) provide quite detailed information on areas in Ancient History. I remember doing Mycenae and finding a university site with incredibly comprehensive information on Bronze Age Greece (something like a thousand pages, 3/4 of it I found relevant to the course).
I think that all people studying history are historians, but you can still say that some are more reliable/ useful than others (yes, I did Extension, and continue to study equivelant courses at university). I'd much rather read Herodotos on Ancient Greece than many modern scholars, although Herodotos' methodology is outside what is normally understood to be history. Also, I'd rather read Thucydides than Plutarch on the Pel. War- surely we can make these kinds of judgments on who is more qualified than others?