XZ2 Premium has UHS as part of Auto Superior, it kicks when necessary and no need to go to special menu. Also it works for videos. Which makes its 1080p look better than 2160p of other under these conditions.
Of course Mate Pro would win, the hardware difference cant be matched by software . Pixel has hardware limitations, impossibe to ask more from 1/2.55"
I'm not a fan of these night modes, they give the final image a weird look, like they've been overprocessed.
The only phone I know about that is capable doing as good if not better than these while being natural is the XZ2 Premium, a comparison between these phones should be great. Moreover, the Sony way is useful for video recording, not only pictures.