When two of China’s leading AI pioneers went public in Hong Kong in January, they pitched investors on a shared promise: capturing the explosive demand for artificial intelligence at home and abroad. Their first-half earnings, however, suggest that narrative could be splintering into two different trajectories. While Beijing-based Z.ai, also known as Zhipu AI, is winning over market analysts on the back of surging revenue and top-tier model performance, its Shanghai rival MiniMax is facing...