The trinity, party responsibility, and how to try and improve the game from within

[Silica-chan]

10X this. Even more so, make the penalty apply doubly and to the entire party, not just DD's. -25% tome rewards for everyone if tank or healer outdpses the DPS, -50% if both are true. Otherwise, the system would be too easy to abuse.

Or you could just reward people for doing more than they are required to complete something.