Well, you could try to add classes that are similar to the classes you have now. Balance druids are similar to shamans. Or a feral druid and a rogue are pretty nice as long as you can effectively manage the 3 melee classes (your pally + 2) plus you have a benifit of another 'oh shit' button on either. Battle res for the druid and if you take engineering on the rogue, vanish/jumper cables (get the XL's significantly higher sucess chance)