I have no issue with a core 4 person party as long as I can hire additional mercs, tame beasts, have NPC’s for specific quests join, etc...
There are multiple ways to cook a goose and whilst I love the 6 man party aspect of BG1&2, I believe the focus here is on the story and interaction of the core party. So that’s fine by me, as long as I can artificially inflate the group for those epic moments, or in order to have a weird and colourful group composition.
I don’t need 6 heavy story based characters in my party at all times, I mean I’m not against it, but you do build in more replayability by limiting which of the story characters you have taken this playthrough.
Again, I’m not anti 6, I just think this discussion is perhaps too focused on it being black or white, where I do think Larian is considering some middle ground and considering the multiplayer aspect.