I know this is stupid but... i'll ask anyway. 
 
First, if you create a match with just friends do the trophies count? 
 
This et tu brute trophy is stupid because you have to happen to be playing against people on your friends list which i am guessing is not *that* common of a thing to happen, certainly not for me anyway. So... 
 
anyone looking to get this trophy or any others, this is a call for help. ***HELP*** :)
 
Hit me up on PSN. Maybe if we can get a good number of people we could set up a time like Friday Aug 6 from 8pm EST until whenever, and we could all get it pretty quickly. 
  
Anyhow, anyone interested? Add me on PSN: flannelbeard

Count me in.  And I'd buy Onslaught if I had people to play with regularly.
 
PSN:  Niemand-II