Well, sounds like it ...
Mercenary can be poor substitute, but i want to believe that they will be there just as "last possible solution" ... for those of us, who will create so unbearable character, so it would end allone anyway.

I dont want to offtopic with first coment, but i feel the urge to mention that 6 member party will solve this problem ...
Since as many people are complaining ... your party in BG-3 is bound to be effective, you need someone to pick locks, you need someone to pass strength checks, you need someone to support, and you need someone to deal damage ...
While many classes can do more than one of those at once ... you still kinda need to count your power, so your party is more determined by "what class do YOU play" than "wich companion you like the most and therefore wish to bring him on adventure".
Also im quite convinced that "comitment past Act1" Larian mentioned means that we will simply pick one companion, wich story we will follow until main plot cross our path again.

And i do believe (feel free to read as: want to believe) that once we will comit, we will unlock non-origin (aka non-tadpoled) followers aswell.
So i believe this will not be so harsh.
