Bab 108: 108 Chapter: Wang Ba's Path does not Need Allies.

...

Yu Jin was reliable enough, and Lub Su was patient and capable. With ten thousand men firmly stationed at the border, it wasn't going to be easy for Cao Cao to defeat them, even with Xi Zhicai, the Two Xuns, and Cheng Yu on his side. Defense often held a greater advantage over offense. As long as they could hold the front lines, once Chen Xi finished repelling the Yellow Turbans and returned, the situation would be reversed instantly.

As for the troubles Cao Cao might have as Governor of Yanzhou, let's be realistic; provocations may occur, but in the end, it would still come down to a comparison of martial force. As for Cao Cao's desire to seize grain in Xuzhou, with Mount Tai blocking the way—a gateway to Xuzhou—Cao Cao would have no choice but to fight if he wanted to get through. Forget about any other methods.