Correct me if I'm wrong, but isn't there more to graphics than resolution? Shaders, lighting, and different setting apply to graphics. PES has way more things going on than FIFA. Look at the picture posted above, PES has higher quality models than FIFA.
2) It doesn't work that way. Your thinking is flawed.
3) Like I said, more to graphics than just resolution. X1 most likely has better Shaders and aliasing.
4) Do you see Ground Zeros? 1080p 60fps on PS4 vs 720p 60fps on X1. And the PS4 version has a dynamic cloud system versus the static clouds in all other versions. FOX engine also ran great on the X1 as well.
I think people have been getting used to the parity seen in the last couple of games and forgot about the difference between the PS4 and X1.
Edit: Good job Chobel
I may be off the mark, but based on this I have to imagine that you haven't spent any serious amount of time with PES or FIFA.