Yeah i gotta agree with people here, 4 party membrs just doesnt feel right.

Now heres why i think that is.

Anyone remember the Divinity spinoff?
The XCOM one that got cancelled?
Now they introduced more than four characters in that one, due to it beeing more about the TBT aspect.

Now what they did in that game was to remove the Divintiy style initiative order and go with an XCOM like Initiative order so "Team good guys" and "Team Red China" alternate rather than the party members having individual turns.

The same appears to be ture for BG3.
To me this doesnt realy add up. The entire reasn to only have 4 characters was the limitaiton of turn times.
Im gonna be honest, im gonna play this game in Multiplayer and id prefer to controll 3 charactrs opposed to just 2

ESPECIALY since this is DnD 5e and some player is gonna be stuck with the Fighter i,e one character who mostly does " i hit thing" and whose most interresting combat stuff is gonna be throwing his boots or kicking people around by the looks of it