When Faydaen returned from his expedition to the middle city, his hometown was already more or less rebuilt, and a sufficient army had been gathered to easily capture the eastern city.
There were also some minor losses during the assault on the central city and when dealing with the neutral forces blocking the way. I wasn't very lucky at that point. It was a week of strong neutral creatures, which a level 1 hero couldn't defeat without losses. They blocked the path, and I decided that Faydaen could handle it without reinforcements.