IMHO 4 can be fine as long as they do the following.
1. DO NOT KILL OFF THE OTHER COMPANIONS AT THE END OF ACT 1!!!
2. Allow for easier switching of characters during play (not just when at camp)
3. Allow for equipping of characters at camp.
I have to say my ideal way of playing small party games with "camps" (from KOTOR onwards) has been switching up parties frequently depending upon the mission. And I particularly like cases like KOTOR2 or DA:O when you get a mission your main character is sidelined and you need to send a "B team." It gives the game far more of a "cinematic" feel.
