While playing the IE-games (apart from PST) I always form parties consisting of three melee classes, usually paladin+fighter+cleric and 3 ranged classes, usually ranger or bard+rogue+wizard. This system developed after playing PST where you just crowded the enemy with up to 5 melee fighters and 1 ranged classes, though mostly I used 4/2 after obtaining Nordom. When fighting in narrow corridors this is (for me) not advisable unless one or more of the meleetypes are using pikes or halberds and just jabbing at the enemy over the shoulders of the frontliners because they otherwise can't touch them. Even using 3 melee guys can cause the third guy to just have to stand around twiddeling his/her thumbs, unless it is a supportcaster like the priest. Reading the descriptions of the classes I understand only the ranger will be a good ranged class. The wizard will be (only?) slinging spells and the rogue will be mainly melee. Fighters can be second to rangers, as in: "while fighters are often thought of as being primarily melee-based, they can specialize in a variety of weapons, including bows, crossbows, and even firearms. They're unlikely to outclass rangers at their own game, but fighters can be almost as dangerous at a distance as they are up close".
But what about the others? The chanter, the druid and the cipher? The cipher reads as another melee type, as in: "wielding knives engulfed in purple flames that "cut away" the souls of their victims". The druid also seem to be mell-oriented.
The 3/3 system has always worked best for me in all of the IE-games (apart from PST). I dislike equipping everybody with a second weapontype (melee vs. ranged) and investing those scarce skillpoints in a skill I seldomly use. I use vanilla classes because I get a headache from munchkinising to get übersuperduperfantasticawesomeleetz ninja/pirate/barbarian/wizards who can tackle the game on their own.