At this point I'm expecting 0-2 more Origin Companions, and 3-5 non-origin companions. Hopefully, in the terrible case where Larian does decide to kill off origin companions that aren't in our party, we'll still be able to have >3 companions through these non-origin ones.
Karlach=paladin, Halsin=druid, Alfira=bard, Minsc=ranger. All seemingly non-origin companions, although Karlach does have
a tadpole, I think... She claims that she boarded and stowed-away in Avernus, which means she wasn't captured and implanted??? But there is a clear telepathic connection to her and a dialogue option where the PC asserts Karlach has a tadpole in her...I'm a bit confused.
Anyway, this means she could be an origin companion, or at the very least a companion who would be unceremoniously killed off if Larian goes that route, so close enough.
We'd need: barbarian, monk, and sorcerer. I highly doubt there will be an artificer companion.