NEED!!

As i was totaly and completely bored (and i rostered myself out of the Karazhan raid yesterday in favor of others even tho i wanted to go there) i decided to try some alting. My Shammy is my current project who has the lovely age of 40 at the moment.. so i logged her and signed up for Scarlet Monastery in a weak moment.
Soon i found myself in a party with 2 Druids, a Hunter and a Enhancement Shaman (as i am). As i feared none of us were healing specced or even had a spec which would at least guarentee a reasonable ammount of mana.. like moonkin or elemental.
The other elemental shammy was 8 levels higher then me so he had the most mana and was going to heal. For some reason he went AFK alot and he arrived late so i had taken up the task to heal a large part of our run.. running out of mana on each pull forcing me to stop for a drink.
The Feral tank quickly found out i was out of mana when he ran ahead, dragged back a shitload of mobs and then got floored due to lack of healing.. i filled up my mana and then assisted the others in killing the mobs so no wipe but the lesson was learned :)

After a succesfull run the Hunter bailed and got replaced my a Paladin, he was Retibution but had a healing set so i could do a poor attempt at dps that time. But then the NEED discussion started; "Who needs the mail gear?". The other shaman and i said we did so the Paladin told us he did aswell.
Uhm, but Paladins can wear plate at 40 cant they? I personally wouldn't roll on Leather gear for my Hunter when a Druid of Rogue could use it, sort of Classneed > Need. He thought otherwise... now we could have booted him right there (altho i couldn't as i wasn't the leader) but i decided to not make a fuss out of it. Losing a mail item to a Platewearer would not feel right but he did warn us in advance and we had the choice to replace him right there.
Besides getting a group for an low level instance is quite a pain nowadays so i was happy to just have a reasonable group for a change.
In the end Scarlet Leggings dropped which the paladin already had and i was lucky enough to outroll the other shammy.

But i guess this was another example where it is important to agree upon priorities in advance, if the paladin would have rolled need without warning us in advance he would probably been yelled at. I would have done the yelling myself but i surely be pissed off.
I've set up loot priorities before in the past often looking something like: Classneed > Need > Greed.
Now these priority sums can be made as complex as you want, when doing our Karazhan run which are often mixed main/alts we use Main > Alt aswell and Spec > offspec. This would result in: Main > Alt > Offspec > Greed. Classneed is not used in that list as i think that is an obvious thing in our guild. (most of the time anyway ;-) )
But we have more priority sums; as we have different ranks in our guild this also goes for raidspot where Honored > Friendly > Neutral.
(Higher ranked people have more responsibilities aswell so they get raid priority in return)
Now you can have billions or rules and lists like this but still something can happen which aint perfectly described and fit somewhere in a gray area and needs to be sorted on the spot, or a person simply reads the rules in an other way then they were ment.. again resulting in possible discussion.
So i guess you just try to stay as close as possible to pre-set rules and try to make as many people as possible happy... in the worst case scenario we can agree to disagree and leave it to that.