Question: why are there 2 fullmetal alchemist series?
Answer: There are two versions because, The first one, Fullmetal Alchemist, was going at a faster rate than the Manga was. So the producers put in their own version of the story and voila! ... The second one, Fullmetal Alchemist Brotherhood, however, is based purely on the manga, and therefore garnered much more views and reviews.