In BG3 we meet all companions in a very short period of time.
We dont exactly know if what we have right now is "all" companions ...
Actualy, concidering datamined info, and some old interviews ... we can be quite sure it isnt.

But yes, we meet them all pretty soon ...
And many of them we can also pretty soon either loose, or even straight forward kill with our own hands.

I still dare to presume that we will leave most of our party (in my honest opinion everyone except single Origin character we will follow to Act II.) ... since once our tadpole problem will be solved, we would no longer need to stick together.
This thread should really be in the megathread.
Agreed ...
I asked for merge few days ago, but sadly no response. :-/