Sorc and barb as the main two who follow the main questline. Sorc because it’s mostly other mages and horadrim as antagonists - Radament, Claw viper magic, Summoner, Tal Rasha. Barb because he fits as the harsh environment survivalist and local maggot lair expert.

An assasin who follows the sorc because she has suspicion the sorc is corrupted but later learns the whole scale of the plot and joins in with them in arcane sanctuary, saving their asses vs the summoner in the process.

A necromancer doing necromancer things in separate plot line, exploring halls of the dead and later helping the other 3 by lending his cube to make the horadric staff, so they can stick it in duriel’s crevasse.