Wei Zikua was an inspector whose responsibility was to lay the groundwork for the Myriad Domain plan. On the other hand, Cao Jin didn't care about such matters. As a genius disciple, the only thing he looked to was profit, so he wasn't in the least interested in the Myriad Domain's overall situation. What he was interested in were the earth and sky rank herbs. How could Cao Jin not be moved when he heard that Jiang Chen had received a hundred earth rank herbs? Not to mention the extra seven sky rank herbs he held!
Both Zhu Changsheng and Elder Tan Lang had played a little trick by deliberately omitting the fact that the sky rank herbs might be with Jiang Chen instead of the Regal Pill Palace. All they wanted was to instigate matters and see misfortune fall upon the Regal Pill Palace.