Instead of a Reroll System SE should go the route that WOW has taken. Drop Gear tokens.

Gear Tokens just like the ones in Snowcloak, Sastasha and Sunken Temple. except mod them a tad.

The gear tokens will share a few classes like;

PLD/WAR
SCH/WHM
BLM/SNM/BRD
MNK/DRG/NIN

Now these are just examples of the Job Groups, but this way loot will not be wasted as much, and it will still have the RNG factor if say your Healers alrdy have the Helm, and the healer Helm token keeps dropping.

So now no more Drg shit dropping when no1 is a Drg Main.

Where as nothing will be wasted, and its on the group to decide who gets what.