Oh yes, I did think this through, thank you very much.
There are 4/8 people in a group and these 4/8 people kill the boss.
That means ALL 4/8 members of the team accomplished the task equally.
Hence, ALL 4/8 members of the team are entitled
to roll on the loot.
It is IRRELEVANT if they can use the item or not, they are still entitled to the roll because they all did the work.
If you argue that, I question your sense of fairness and this discussion might as well end right here.
Ideally, loot would be awarded individually to all 4/8 members, taking their classes in consideration.
But we don't have such a system. We only have "need", "greed" and "pass".
The new addition that allows people to trade items actually complements my idea very nicely:
Let's say my sniper wins the roll for a lightsaber and the marauder in my group wants to have it.
Since we now can trade, I can sell the saber to him and we both are rewarded for killing the boss.
I still suggest that we all only use "need" and let the random generator decide for groupfinder teams.
It's as fair as it can be with the current loot system.
Although I come to believe that people rather want to stick to a messy, injust "social contract" (and then complain about the violators) then push for something that is objectively fair and equal.