Well... the state alchemists were only brought in in the last six months of the war, if I remember correctly, so the war itself could have gone on for 12 years before it was finally brought to an end by the state alchemists. Now, here's the question. Does Marcoh say the war BEGAN or ENDED 13 years ago? I suppose I should go watch the episode myself. But I do agree that Roy was pretty young when he was sent out like that. Probably explains some of his reasons for helping Ed too.