Yeah I have to agree that the party size reduction automatically makes it impossible for me to be willing to take along not just animal companions but even other odd-ball or unusual or quirky companions. My three companions would be chosen in a very structural way to cover what I consider to be necessary party functions, and NOT on the basis of who's most interesting. A sad fallout from the party size reduction decision.
Didn't Larian say it would be possible to beat BG3 through dialogue only? I imagine you would be able to complete the game with any party or just going solo, so personally I would take all the odd-ball, quirky and unusal companions.