Neonchameleon
Legend
This whole idea of balance complicates the game way too much. If you really want balance in a game that has 5-6 encounters in a 6-8 hour game, then you design each encounter to bring one or more of the characters to the forefront.
I read a statement like this and my eyes cross. I design the monsters plans to reflect the gameworld, or to reflect the PCs desired approach after they've told me what it is. Twisting the world to fit the characters first is something I consider to be a railroad in a bad way - I'd far rather run something sandboxier (and play something sandboxier) and second turns the creativity of players into an attempt to get into my head rather than an attempt to solve the situation on the ground. I emphatically never fix one way out of a situation or throw it to just one PC - and I find doing so cheapnens the game. (Which isn't to say some situations are better for some PCs than others. But not that I start plotting like that except for special occasions).
And I emphatically disagree with your most recent comment. It should not be the job of the DM to fix a broken game. It absolutely is the job of the rules to provide a decent resolution system and to make things easier for DM and players to all get onto the same page and match the desired fiction. In fact I would say that the rules have quite literally no other purpose than improving visualisation and assisting with conflict resolution, and balance is an essential part of satisfactory conflict resolution.