Leica Q-P has a 24.0MP Full frame (36 x 24 mm ) sized CMOS sensor and features Maestro II processor. On the other hand, Zeiss ZX1 has a 37.0MP Full frame (36 x 24 mm ) sized CMOS sensor .
Zeiss ZX1's sensor provides 13MP more than Leica Q-P's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
Below you can see the Q-P and ZX1 sensor size comparison.
Leica Q-P and Zeiss ZX1 have the same sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture. On the other hand, since Leica Q-P has 55% larger pixel area compared to Zeiss ZX1, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.