no my friend
these pictures are matched and measured from the whitest to the darkest and the same curve , the white point is the same, but Im looking after resolution
and if you do not se any difference in resolution you have some problem
se the wall at the X
and yes you se some more noise because of 36Mp and 100%
You are making an incomplete argument. Yes, 36mp is higher res., with smaller pixels, therefor more detail and more noise (which, ironically, is the same issue with the 7D). You made the argument that you could just downscale to the 5D III size, and that noise would be the same. You are failing to point out that if you downscale, you no longer have a resolution advantage. All that extra detail you claim to see (I only really see sharper wires in the fence...detail-wise, the rest looks the same to me)...well it would all be gone. Its the whole having a cake, and eating it too problem. You can have your pretty high resolution cake, but to eat all the noise...well you gotta eat all the resolution too.
BTW, these two shots were clearly taken at different times of day. The shading is quite different between the two, which changes which details can be clearly seen. The D800 shot is also darker by maybe two thirds of a stop than the 5D III shot. In the D800 shot, the right side of the building looks blown...with all that extra DR, I wouldn't have expected blown highlights...maybe some recovery would fix that. Only the trim looks like it might be blown on the 5D III shot...but it would be interesting to see if, pulled down by 2/3rd stops, if that remained true.