Even knowing about this "feature" I still sometimes forget to bring party members into combat if they are stealthed, or too far when combat starts.
It's simply so counter-intuitive that you don't think about it and end up missing turns on some characters. Being able to exploit it is hardly a good way of "balancing" it.
It would help if the combat radius would be greatly increased to the point where it would be impossible to forget your characters, and exploiting it would be much more difficult. Invisible or stealthed characters in combat radius should automatically enter combat.
