Besides that, balancing might be even more troublesome for them, plus with only like six to ten companions at the end, parties might look very samey every time you start a new game.
I donìt get this argument. Aside for the fact that "only six companions" would be disappointing regardless of party size, if anything reducing the number of slots is going to make me even more wary of experimenting with the occasional odd class/specialization. When you have only four slots, each one of them becomes even more valuable to cover for a key role, rather than trying fancy combinations and synergies.
Party control in Baldur's Gate 3 is a complete mess that begs to be addressed. SAY NO TO THE TOILET CHAIN