Would be nice to be able to sort groups by how many of an armor type they have, like more than 2 leathers or something like that. Makes it easier to get potential gear traded or trade to others in PUGs.

• For 4 plate :

((warriors == 4) or
(paladins == 4) or
(deathknights == 4) or
(warriors == 3 and paladins == 1) or
(warriors == 3 and deathknights == 1) or
(paladins == 3 and warriors == 1) or
(paladins == 3 and deathknights == 1) or
(deathknights == 3 and warriors == 1) or
(deathknights == 3 and paladins == 1) or
(warriors == 2 and paladins == 2) or
(warriors == 2 and deathknights == 2) or
(warriors == 2 and paladins == 1 and deathknights == 1) or
(paladins == 2 and deathknights == 2) or
(paladins == 2 and warriors == 1 and deathknights == 1) or
(deathknights == 2 and warriors == 1 and paladins == 1))

• For 3+ plate :

((warriors >= 3) or
(paladins >= 3) or
(deathknights >= 3) or
(warriors >= 2 and paladins >= 1) or
(warriors >= 2 and deathknights >= 1) or
(paladins >= 2 and warriors >= 1) or
(paladins >= 2 and deathknights >= 1) or
(deathknights >= 2 and warriors >= 1) or
(deathknights >= 2 and paladins >= 1) or
(deathknights >= 1 and warriors >= 1 and paladins >= 1))

• For 2+ plate :

((warriors >= 2) or
(paladins >= 2) or
(deathknights >= 2) or
(warriors >= 1 and paladins >= 1) or
(warriors >= 1 and deathknights >= 1) or
(paladins >= 1 and deathknights >= 1))

• For 1+ plate :

((warriors >= 1) or
(paladins >= 1) or
(deathknights >= 1))

• For 4 leather :

((druids == 4) or
(druids == 3 and rogues == 1) or
(druids == 3 and demonhunters == 1) or
(druids == 3 and monks == 1) or
(druids == 2 and rogues == 2) or
(druids == 2 and monks == 2) or
(druids == 2 and demonhunters == 2) or
(druids == 2 and rogues == 1 and monks == 1) or
(druids == 2 and rogues == 1 and demonhunters == 1) or
(druids == 2 and monks == 1 and demonhunters == 1) or
(druids == 1 and rogues == 3) or
(druids == 1 and monks ==3) or
(druids == 1 and demonhunters == 3) or
(druids == 1 and rogues == 2 and monks == 1) or
(druids == 1 and rogues == 2 and demonhunters == 1) or
(druids == 1 and monks == 2 and rogues == 1) or
(druids == 1 and monks == 2 and demonhunters == 1) or
(druids == 1 and demonhunters == 2 and rogues == 1) or
(druids == 1 and demonhunters == 2 and monks == 1) or
(druids == 1 and rogues == 1 and monks == 1 and demonhunters == 1) or
(rogues == 4) or
(rogues == 3 and monks == 1) or
(rogues == 3 and demonhunters == 1) or
(rogues == 2 and monks == 2) or
(rogues == 2 and demonhunters == 2) or
(rogues == 2 and monks == 1 and demonhunters == 1) or
(rogues == 1 and monks == 3) or
(rogues == 1 and demonhunters == 3) or
(rogues == 1 and monks == 2 and demonhunters == 1) or
(rogues == 1 and demonhunters == 2 and monks == 1) or
(monks == 4) or
(monks == 3 and demonhunters == 1) or
(monks == 2 and demonhunters == 2) or
(monks == 1 and demonhunters == 3) or
(demonhunters == 4))

• For 3+ leather :

((druids >= 3) or
(monks >= 3) or
(rogues >= 3) or
(demonhunters >= 3) or
(druids >= 2 and monks >= 1) or
(druids >= 2 and rogues >= 1) or
(druids >= 2 and demonhunters >= 1) or
(monks >= 2 and druids >= 1) or
(monks >= 2 and rogues >= 1) or
(monks >= 2 and demonhunters >= 1) or
(rogues >= 2 and druids >= 1) or
(rogues >= 2 and monks >= 1) or
(rogues >= 2 and demonhunters >= 1) or
(demonhunters >= 2 and druids >= 1) or
(demonhunters >= 2 and monks >= 1) or
(demonhunters >= 2 and rogues >= 1) or
(demonhunters >= 1 and rogues >= 1 and monks >= 1) or
(demonhunters >= 1 and rogues >= 1 and druids >= 1) or
(monks >= 1 and rogues >= 1 and druids >= 1) or
(demonhunters >= 1 and monks >= 1 and druids >= 1))

• For 2+ leather :

((druids >= 2) or
(monks >= 2) or
(demonhunters >= 2) or
(rogues >= 2) or
(druids >= 1 and monks >= 1) or
(druids >= 1 and demonhunters >= 1) or
(druids >= 1 and rogues >= 1) or
(rogues >= 1 and monks >= 1) or
(rogues >= 1 and demonhunters >= 1) or
(monks >= 1 and demonhunters >= 1))

• For 1+ leather :

((druids >= 1) or
(monks >= 1) or
(demonhunters >= 1) or
(rogues >= 1))

• For 4 cloth :

((mages == 4) or
(priests == 4) or
(warlocks == 4) or
(mages == 3 and priests == 1) or
(mages == 3 and warlocks == 1) or
(priests == 3 and mages == 1) or
(priests == 3 and warlocks == 1) or
(warlocks == 3 and mages == 1) or
(warlocks == 3 and priests == 1) or
(mages == 2 and priests == 2) or
(mages == 2 and warlocks == 2) or
(mages == 2 and priests == 1 and warlocks == 1) or
(priests == 2 and warlocks == 2) or
(priests == 2 and mages == 1 and warlocks == 1) or
(warlocks == 2 and mages == 1 and priests == 1))

• For 3+ cloth :

((mages >= 3) or
(priests >= 3) or
(warlocks >= 3) or
(mages >= 2 and priests >= 1) or
(mages >= 2 and warlocks >= 1) or
(priests >= 2 and mages >= 1) or
(priests >= 2 and warlocks >= 1) or
(warlocks >= 2 and mages >= 1) or
(warlocks >= 2 and priests >= 1) or
(warlocks >= 1 and mages >= 1 and priests >= 1))

• For 2+ cloth :

((mages >= 2) or
(priests >= 2) or
(warlocks >= 2) or
(mages >= 1 and priests >= 1) or
(mages >= 1 and warlocks >= 1) or
(priests >= 1 and warlocks >= 1))

• For 1+ cloth :

((mages >= 1) or
(priests >= 1) or
(warlocks >= 1))

• For 4 mail :

((hunters == 4) or
(shamans == 4) or
(hunters == 3 and shamans == 1) or
(shamans == 3 and hunters == 1) or
(hunters == 2 and shamans == 2))

• For 3+ mail :

((hunters >= 3) or
(shamans >= 3) or
(hunters >= 2 and shamans >= 1) or
(shamans >= 2 and hunters >= 1))

• For 2+ mail:

((hunters >= 2) or
(shamans >= 2) or
(shamans >= 1 and hunters >= 1))

• For 1+ mail :

((hunters >= 1) or
(shamans >= 1))

I added keywords plate, mail, leather and cloth for number of chars with this armor type in the group.