I'm a pve player and I completed mine in a few games. Just don't think you have to play fair. I had a couple amazing 3.0 kd games where I was just corner camping with the last word the entire time and stealing teammates kills. This quest really loves multi kills and killing sprees. If you're really that bad, you should only switch to last word when you have heavy and your super is up. I just threw a few hammers and got an easy triple kill. Follow it up with a few rockets. You also get 3% for winning the game.