4 shaman+mage viability in heroics?

[Nokku]

Would a team of 4 shaman + mage be able to efficiently do heroics just as a 5 shaman team? My mage already has good gear and it will be much easier to level 4 shamans than 5. Also, portals will be quite useful as well :D

[Kaynin]

As easy as 5x shamans I reckon.

Some fights will be easier with an extra sheep. But you'll have trouble in some heroics.

[Crucial]

It's possible to do some heroics even with 4 shamans (slave pens 1st two bosses for example), so I would definitely see it being easier with a sheep unless the mage is constantly getting agro and one shot to death. What I wouldn't give for mage water with my all shammy crew...

[Nokku]

I don't think I'll need to sheep at all with this kind of firepower. Only have two worries about this setup - first, mage pulling aggro and dying (fire spec is only -10% threat and I can't really respec to arcane for -40% threat), and second, that some fights might not be doable with 4x totems instead of 5x.