Of course, they knew, but at this time, they didn't have many good options. Because at this point, the court had almost no room left for those in favor of war.
The Jin soldiers from two routes were unstoppable, and the Qi Dynasty's army was repeatedly defeated, even their raids on the enemy camps had failed.
These defeats led the Emperor to place all the blame on the pro-war faction, beginning a relentless suppression and exclusion of them. Even a capable official like Li Boxi was repeatedly suppressed, relying on the surging public opinion in the capital to retain his position. What more of the rest of the pro-war faction?
Thus, for the pro-war faction to survive in this court that had turned into a vast whirlpool, they needed a significant victory.
They hoped to swiftly recapture Taiyuan and prove themselves with a significant victory.