So they do downsampling until the camera they want to be better is better... don't know.... sounds strange, but is not subjective at all
Its one of those situations where a comparison is not really possible. Using their method, a high MP body will be much more likely to have a higher score, but the high MP is not the whole story.
I like high mp bodies so I can crop and still have a good image left, and at low ISO's, the Sony sensor is good. that's assuming that I'm willing to buy a $5,000 Zeiss lens that can produce those results. In any event, with a ordinary lens, the results will be better than with a low mp sensor.
At high ISO levels, when you crop, the noise comes into play, and the image can look really poor.
If they cropped the images to 8mp, the results would be a disaster, so here is no ability to do severe crops at high iso's.
Its not really possible to do a single comparison that tells the whole story, DXO tries to simplify the results, and many think that their numbers are the whole story.