Although Carl had hoped to wait for the arrival of the dwarves before starting the war, regrettably, the Chaos Army was clearly not going to act according to their plans. Perhaps the Chaos Army had also learned about the aid being sent by the dwarves, so they quickly prepared to launch another attack on the United Army.
Faced with this situation, Carl had no choice but to confront them again.
Although technically speaking, holding out in Midheim would be a good idea, the problem is that while Midheim has blocked the main transportation routes, it has not blockaded the forests and wilderness around it. If they cannot consolidate their advantage on the battlefield, the Chaos Army can completely bypass Midheim and launch attacks on other imperial cities. Furthermore, they have the assistance of the beastmen who are familiar with the Black Forest. So, to avoid this situation, Carl had to take the initiative to attack.