Cheng Su had two reasons for having Ning Ge make the call. First, she wanted to know his real situation, to avoid being sold without even realizing it. Although Regimental Commander Mai had confirmed it before, it's always better to hear it confirmed with one's own ears. Second, since they were going to cooperate, it was only fair to let the other party know about their situation too. This way, both parties knew each other's backgrounds, and if anything happened, they could find someone to hold accountable. She wouldn't have to fear that later on, someone would accuse her side of having tricked Ning Ge.
Indeed, when Ning Ge proposed the partnership, Cheng Suxin's inclination had already leaned towards agreement. Only a fool would turn down the chance to make money. With someone offering to invest capital and herself possessing the formula and technology, especially at such an opportune time to seize economic growth, why shouldn't she do this business?