Scoring system

I have been wondering if some info exists to explain the scoring system deciding your team rank at the end of battle? Intuitively, when I look at how I did compared to other team mates after battle (tank battles), it feels as if "enemy kill assists" give you more points than actual tank kills or capping? For example, I often have more kills and caps than players above me, but they may have more assists. If there is something to this observation, it's kind of an odd incentive for players, as it is easier to stay with the pack and get some "assists" rather than risking your neck capturing caps and killing tanks on your own (or being the leader of the pack risking enemy fire), which has more weight on the battle outcome? I am not trying to raise any issues here, just want to understand things better - Thx!