In any war, the side that started the fight first would always have many advantages. The most important benefit was the initiative. You would be able to fight at a location of your own choosing that you planned for.
If you still couldn't gain an advantage from this, that meant there was a difference in power level that even strategy and tactics couldn't make up for. It would be quite difficult for you to win in such a scenario.
Just as the humans' command center expected, starting a pincer attack on two battlefronts pressured the devils greatly. The dragon knights, elite squads, and countless balls of Holy Light on the eastern battlefront that started the fight first suggested the humans were determined to make this the final battle, but this was actually just a distraction to attract some of the devils' forces.
