I've now got about 30 hours in the game, and the number one issue I have is that the party size is too small, by at least one character. And I firmly believe the reason has to do entirely with Divinity: Original Sin.

In BG3, you have a party of characters who must work together to achieve their shared goal(s). To be successful, the party will generally require the following things:
- A healer who can keep the party on it's feet.
- A tank of some sort who can help protect the squishier folks and dish out some damage.
- A magic user who can provide access to mystical tools.
- A utility character who can accomplish tasks like opening locks, disarming traps and generally being rather sneaky.

In a system with a maximum party size of 4, and all characters using a class based system, it is extremely difficult to cover all of these needs and still have room to bring along a party member you're fond of who already has their class-based role filled. For example, if I want to play a Warlock, it is rather difficult to bring Wyll or Gale with me without handicapping my party's capabilities. (Yes, I know Gale can learn healing spells right now, but that needs to be addressed as well).

Larian was able to get away with this in DOS because they did not use a fixed, class based system. Any character could learn any skill in the game, so you could completely mix and match your companions with the ability to train or rebuild them to ensure good party composition. BG3 on the other hand uses classes, and while we will eventually be able to multiclass, I think that will struggle to provide the flexibility needed to have party members who can excel at their role and still cover a secondary role to a sufficient enough level to free up a party spot. This leaves the player in the unfortunate position where their party composition will generally be dictated entirely by class and role, with no room for personality or character interest.

Getting the party size to six is likely a rather unworkable solution when it comes to balance and performance, but I really hope Larian will consider increasing the size to five to allow players to bring along their favorite companion, even if they are a bit redundant or ineffectual.