I hate the idea of having to choose 3 companions and loose the rest, I want to have choices. What kind of mechanism is that? I mean, I'm ok with loosing one or maybe two companions due to story or approval reasons (I think by the end of the game, Astarion will hate most of my characters, might as well sell him to Cazador and make some profit)., that happened in the old games too, but not all of the not active party members.
I don’t like it either.
But it might be that the ones you don’t choose become your adversaries. Now that would be nice. I wouldn’t mind justifying killing some of my companions other than just being a murder hobo. I could see Asterion and Gale choosing to keep the tadpole to enrich their power.
Or for evil characters, the lost companions will want to stop the evil character from gaining godlike power.