Hybrid damage in raids

first of all i would like to say that i dont want that hybrids cant come to raids to make dps BUT:

25man raid:
lets take theoretical situation:

quite typical 25man raid gruop before 3.0:

mage
mage
warlock
shaman (resto)
priest (shadow)

in wotlk (when hybrids doing about same damage than pure dps (1-3% if blue post was right):

mage
boomkin
shaman (resto)
priest (shadow)
shaman (elemental)

now think abour group damage. if boomkin does 2% less with elemental shaman. group damage will be better with hybrids than with pure damages. Because boomkin and elemental will boost damage to other classes still doing what pure damage is doing.

conclusion:
if we dont count we lost banish and sheep. its much better to take hybrid damages than pure damages because raid damage will be higher, and raid damage is only that matters in high endgame raids. so i think hybrids damage should be little bit lower so both gruops (pure damage gruops, and mixed damage gruops) would make same damage. this means that hybrid damage should lose around 5-10% to pure damage because they allso boost gruop damage.

P.S. i dont want to say it should be low as now with hybrids losing around 20%. i think hybrid damage can be boosted. but i dont think it can be boosted to allmost pure damage level or its better to take hybrid damage to raid than pure damage.