first off, most points are allocated based on damage you do (prevents a totally random reward system)
Second, if you kill someone who has done enough damage you get their points (Promotes killing enemy players to help your team during bosses)
third, All score is given out after the boss dies. (to support both inital parts)
Finally, Killing blow grants a bonus to score for the team that gets the killing blow.
ok.. now how does this work.. lets do some examples... (please feel free to suggest additional Scenarios)
Open the spoilers for the Examples.
another option to how this can turn out is to implement steps for damage...
Open the Spoilers for the Examples.
As you can see, these changes make it not only important to deal damage to the boss, but greatly improves on the need to kill enemy team members attacking the boss while removing the Current Dice roll feel to the scoring system and still rewarding the team that gets the killing blow. its as much of a win win system for everyone preferences as i can think of that only relies on changing scoring mechanics and not anything more.