Leica Q2 Monochrom has a 47.0MP Full frame (36 x 24 mm ) sized CMOS sensor . On the other hand, Sony RX1R II has a 42.0MP Full frame (35.9 x 24 mm ) sized BSI-CMOS sensor and features BIONZ X processor.
Leica Q2 Monochrom's sensor provides 5MP more than Sony RX1R II'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.
Another similarity between these two cameras is that both Sony RX1R II and Leica Q2 Monochrom sensors lack anti-alias (Low-Pass) filters. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moire occurring in certain scenes.
Below you can see the Q2 Monochrom and RX1R II sensor size comparison.
Leica Q2 Monochrom and Sony RX1R II have almost the same sensor size so none of them has any significant advantage over other in providing control over depth of field when used with same focal length and aperture.