Regarding Tyranny, I'm not very fond of how it was implemented because you cannot fail in keeping your companions together. If you treat them badly then their "fear" grow, if kindly then their "loyalty" grow. They stay with you in any case. I actually liked PoE 2 dynamics with characters, where besides your own reputation they had reputation towards each other and a whole bunch of different moral values. And no matter of your reputation, certain actions cause your companions leave of even become hostile.
That is understandable, while I would argue that losing companions is not fun and that Tyranny did tie consequences to you tying people to you through fear (often leading to a bad ending for the companion) it had the setting tailored around it to make it work. BGIII does not have this luxury at the moment, especially if Larian goes through with party commitment after Act 1. As a matter of fact, I think you will no longer be able to lose companions after Act 1 in BGIII also, considering you lose a bunch of them no matter what.