Xu Tianran's punch was akin to the Seven Wounds Fist—hurting the enemy before injuring oneself.
As the saying goes, the provisions and fodder must go before the three armies move. The reason Shrek and the Three Empires were able to roughly estimate the outbreak of war was because they had factual evidence to rely on.
Could they fight before the autumn harvest? Yes, but that would inevitably mean levying corvée labor, imposing taxes once again, and escorting rations and supplies. Once too many provisions were requisitioned, the common people would simply drop dead for you to see.
Chapter 846