Dexxta you remember the gnome guy(s) that used to play battle a lot? Think they had like 10 athletics, were tenacious yet flighty, had the super powered gnome hats, and also possibly used bamboo spear? All I remember is the buttstabs. So many buttstabs.
Edit: Woops, missed your clarification post. Way back I used to watch Goretooth play when I was dead on siege, he would get a lot of sneaky kills, basically by just biding his time. Armor and mobfests aside, I'd see him taking less travelled routes, waiting for the right moment, a lot of times in transition areas like stairwells. If you just hunt down strays that haven't grouped up with their team, you can help cut down a lot of potential enemy support.