What if... it would give extra roll bonus? for example: 2 Tanks, 1 drop... they both roll need. One must lose.
The next time a tank item comes and they both roll need, the previous loser would get 10 extra roll points... for example:
tank who won previous loot rolls: 47
tank who lost previous loot roll: 38+10 (extra points from losing previous chest) = 48
And it would add extra 10 roll points for every need failed. Something like that and balanced.
It would reset once the initial loser wold get an item.