I haven't checked their armories yet, but looking at the parses for all the fights, your shaman, and mage drastically need to pick up their dps.
*edit* Ok, so i looked over their armories, I cannot comment on the mage, because he logged out in pvp gear, however, that shaman..... that will hold you back alot.
So here we go:
Helmet doesn't have an enchant, or meta gem, or regular gem
No Shoulder enchant
No cloak enchant
no chest enchant
no bracer enchant
no glove enchant, or gem
no gems in belt, or belt buckle
no gems in legs, or enchant
no gems in boots, and terrible enchant
blue trinket, instead of herukml war token
no enchants on either of his weapons
To top all this off, he is also gemming expertise, while being considerably far above the expertise cap.
Have a sit down with him, and see if you can resolve some of these issues.