Gazing at the great army under his command, Fa Zheng felt a sense of helplessness. If there were more cavalry, they could have launched a rapid attack today and reach Shouchun tomorrow while maintaining their combat power. Unfortunately, Mount Tai wasn't suited for horse breeding and wasn't known for wild horses.
As for buying horses, this was about all they could get. Wanting more was impossible, as Yuan Shao almost completely stifled the horse trade throughout the entire north, making it difficult for such strategic resources to appear south of Bingzhou and Jizhou.
Further south, aside from Yuan Shu who had some horses, others like Liu Biao could barely equip their top generals with a single steed, let alone form a cavalry squad; that was simply a dream.
Of course, this wasn't to say there were no horses in the south, just that southern horses weren't suitable for riding. They could be used for hauling stuff but fell short when it came to warfare.