Well the closest person below that beat us that update was VE, who is a full point behind and the closest person ahead of us was NATO who is almost 2 points ahead.
I believe it's Total Ns/300,000 + Total members/total nations(This for every nation in an alliance, which leads you to about .01 per member)
It's this or something very close.
I remember in GwIII someone posted a battle report where someone attacked their nation and lost 205k soldiers and they only lost 5k. I believe the thread was titled "My troops fight like Spartans"
Personally I've killed 27k in one attacked sacrificing 16k of my own troops.