I would have only Tav and nobody else I'd be enthusiastic about. I'd grudgingly take Halsin and Karlach along even though I don't at all care for the druid class (don't care for the animal forms concept) and the barbarian class (don't care for the raging concept). A hard no on empty-suit mercs. A little less hard no on boring retreads from the previous BG games. So don't quite know who my fourth, fifth, and sixth would be (I'd only play BG3 with a mod to increase party size).
