I like this thread so lets start with my first and personal reason.
1). My "gamer group" consists of 5 people. This means that 1 person will have to sit out. Awkward and not ideal. Not sure how we'll solve this honestly. But perhaps we wont have to solve anything because there will be a mod in place at launch. One of the pros with EA I guess. Unless there wouldnt be support for it but I cant imagine why there would be some hardcoded block.
2). Pathfinder: Kingmaker was elevated to my GOAT list with the turn-based mod. The mod also allows for switching between RTwP and TB and the only time I turned it off was when there are too many clusters of more or less harmless enemies. The mod screws with the balance though, as some fights become too easy when you can line up Grease and other CC with milimeter precision. But that aside, I never felt as having 6 players (as opposed to 4) was jarring in anyway, I enjoyed every moment of every fight.
3). We wont convince Larian of anything if 4 player is their vision of the game. Its like with the Turn-Based Absolutists, they just have to accept that BG3 will be turn-based and thats that. But if its not, the ideal solution would simply be to scale EL with party size (just like in PnP!). I wonder how many extra hours of fine-tuning and balancing comes with that though.
4). Larger party size means more variety. I'll give an example from Spiderweb games: The old "Exile" games had 6 players and the new "Avernum" HD remakes you can only have 4. And if you want the Tank, Archer, Healer, Wizard, Rogue and the archetype "Swings a Huge Sword" you cant. Maybe this was the thought behind the 6-man party back in the day? I know there were games with 4 members too (or more) but it 6 seems to have been the standard. This always feel like I'm missing something, like OK I guess I'll make the rogue the archer and the sword-and-board guy will have to heal. But it just not great, you know? Another byproduct of this is loot: you'll vendor so much shiny treasure and thats just sad.
