Originally Posted by Scribe
In the prior Baldur's Gate games we could create a full party if we wanted to run through the game with.

Is that going to be possible here?

According to an old AMA:
Quote
Will all possible companions be available as Origin character options or will there be companions available only as NPCs?

Swen: We are trying to make all characters with backstory available as origin characters. Other than that, you will be able to recruit generic mercenaries and customize these. We’re also planning to allow you to build a custom party from the character creation screen though that most likely won’t be present in early access from the get go.

So the answer seems to be yes.