Allow me to pitch Coldly Furious for a second. Yes, on the surface it seems similar to Patient or Calm, and it doesn't have the same instant gratification of Furious. Shu already dislikes Dejun, but he's willing to work with him as an ally. Coldly Furious will focus on the battle, and with Zhong's information, Shu would now look at Dejun more hostilely, as an ally in name only. With the battle ahead, and the knowledge that Dejun is chomping at the bit to cover himself in glory, and the odds very close to even, this mindset might allow Shu to use Dejun as a distraction.
If Dejun breaks ranks to lead a YOLO charge against Chu Yan, Chu Yan might consider: "Sure, come to me, I'll destroy you piecemeal." Dejun might clear out some bandit rabble and lure Chu Yan into overconfidence. Between Zhang Xiu and the Azure Lances, our heavy cavalry is our big advantage. The majority of Chu Yan's army is going to be trash infantry, and he'll have less cavalry, with most being lightly armed and armored marauders. We also have quite a few crossbows, and in the battle with Boss Zuo, they did work, practically annihilating the enemy cav on our left flank, then turning their volleys on the infantry. If we mass our crossbows with a revolving volley fire, they can dominate one flank again, or split them to the flanks and have them clear the way for our cavalry charge. When the flank attack commits against the infantry, have a small screening force keep the elite bandit cav off our flank, otherwise they can drive the archers from the field.