Sure is about winning, but a lot of the time it can be more teamwork-friendly to NOT attack and just defend and look threatening, while other people do the actual hurting.
For example a pikeman that just keeps cavalry away from the buddies by pointing the pointy end in the horse's direction to prevent them from coming close is just as much as a teamworker as the guys fighting the enemy infantry, even if he doesn't get to attack a single horse.
It's hard to measure those things, but if anything kills is just a measure of being good at getting the last hit in on people. Be it an agi-build person being good at getting into the back of isolated targets, or a high-strength 2h build that chops off the last 60% hp in one hit on something other people are distracting. The distracting people are doing a just as good job, even though they can't two-hit people.
