my point would be that there is a need for extra dialogue anyway to make it believable that companions would join our group and be content with doing what the player says instead of pursuing their own lives/quest.
Simply having the shared tadpole/nautiloid experience , could be a starting point but seems also quite tentatively that all the companions would give up their previous lives, experiences, resources, goals because of this 'shared experience'. Especially given the rather anti-social tendencies of the "evil" EA companions. A simple way would be for larian to give the PC a small but seemingly important advantage right from the start by letting them find something on the nautiloid that the others don't and which legitimizes the PC as group/party leader over the other companions.
I think the fighter stronghold quest in BG2 is a good and simple example of how to address this, most recruitable NPC's can be found in a tavern, however, if they approach you with a supposedly 'urgent' quest request and you decline, they will not just wait there but already proceed to a different location. Especially in the case of Astarion it seems weird that he would simply wait by a campfire for people he probably despises and feels are inferior to him to do whatever instead of just traveling to BG by himself to study his newfound powers and/or go back to his luxurious life... Same for SH, why would she care to wait for you instead of trying to rejoin her shar cult, same for the gith who couldn't care less about non-giths, same for Gale - why doens't he go find his magic food by himself instead of waiting for it at camp and risk auto-explosion, and same for Wyll who is supposedly well able and willing to adventure on his own.
Just trying to point out where the narrative lacks as of now in the hopes it can help someone to make it better, not my problem to think about if and how these things can be fxed, that's what I payed Larian for, right ?
