My favourite custom party was five pretty aggressive characters named Grishnakh, Gorbag, Shagrat, Ugluk and Bolg (2 pure fighters, 1 barbarian, 1 fighter/rogue and 1 paladin). Everyone with Intellect 3 (although Grishnakh was dangerously clever with 5). They still managed to finish the game, including the expansion, at PotD/Trial of Iron but some boss fights took a looong time.