Raid buffs are actually a point against balance, in this case
In the context of something like Void Dais, if you consider just raw damage RDM is third to last but when you factor in raid buffs it falls to dead last. The 600 or so DPS provided by raid buffs aren't saving it from the garbage heap. If Embolden got moved to 8 or 9% it may catch up to SUM
To catch up to BLM (which I wouldn't ask for, just as an example) it would be like 18 to 20%