So that is what I was thinking, but then I thought (and again, this would fundamentally change the game, but in theory) if you removed the tadpole/mindflayers as the main story and added in something else down the line that brought them together... it doesn't seem like it would be that hard.
Coming up with seperate motivations to pursue in an intertwined story which brings them all together for, what (not sure what the final number will be) companions, plus custom does sound rather hard. Plus custom character who can have whatever motivations player will imagine. At this point you are writing 8 different protagoninsts, rather then one protagonist with minor variations. Interactions of every origin with NPCs would need to be different as they are not pursuing same goals.
Seperating party would also have major impact on balance - as it is game is designed for you to play with companions from the get-go. Starting by yourself, let's say as Karlach in the northern part of the map wouldn't be a fun experience, by yourself on lvl1. And making sure that content all over the map is appropriate for lvl1 solo, would mean that this party cRPG isnt' well suited for parties for a large chunk of act1. That just would work - designing content that can be explored on different levels, from different directions etc. would be rough.
added in something else down the line that brought them together.
So you add tadpole or equivalent somewhere down the line or rather it seems to me that what you are really asking for are seperate origin introductions - something to introduce characters before their capture by mindflayers, ala. Dragon Age: Origins/Cyberpunk77. It could be cool, but really you are just adding stuff before game proper (and story proper) kick off. DA:O did some quality worldbuilding with it, but in Cyberpunk I felt those to be rather pointless, and would rather have the game developing protagonist I play, rather then giving me a short introduction with no relevance to the rest of the game.
