The most challenging campaign.

I have a big question about the campaign (the whole thing), and it's directed to the entire forum and the developers. If anyone has reached the "Emerald" mission, they might remember Alaron (the elven king, in case anyone doesn't remember) talking about his actions, which caused the emerald dragons to leave. So, what are these dragons (about 6 of them) doing in Gilraen's army, if it takes them a long time to get to the Burning Sands (again, Alaron's story)?:confused: