For some reason we drifted away from the original question that was really about if the Leica S2 makes technically better images than a Nikon D810, if I recall it correctly.
In that case I would say that far more depends on the photographer than on the device. To start with, the camera needs to be focused correctly. Lens selection obviously matters, but the original posting was more about per pixel quality. The Leica S2 has 2008 era CCD sensor 37.5 MP vs 36 MP. Both have pixels with around 60000 e- full well capacity, which would give the same signal/noise levels in bright areas. The Nikon probably has something like one fourth (1/4) of the readout noise. So the Nikon image would be cleaner in the shadows.
Leica lenses are said to be great, but so can we put great lenses on the Nikon, having the option to use Zeiss Otus and Sigma A lenses in addition to the Nikon lenses. Lens quality doesn't affect tonality, but it may be that less sharpening is with an excellent lens. If you need to stop down for DoF diffraction comes into the play, requiring more sharpening.
Thriving for the best image quality the 100MP backs are the obvious choice, they have up to date sensor technology, best of breed DR and have a healthy advantage in surface area. Leica really needs to consider the Hasselblad GFX and the Fuji GFX. A few more pixels, with great DR and in all probability excellent lenses.