Edward_R_Murrow Are you really claiming that AD&D doesn't have a
"Linear Fighters, Quadratic Wizards" phenomenon? BG2
just happens to feature lots of tough mage fights because Bioware was too lazy to create challenging fighter and rogue opponents?
Nah. My claim's pretty simple: that the way Fighters and Thieves become powerful when utilized by players doesn't play well when used by the AI opposition. To make a Fighter or Thief powerful requires crossing the Rubicon in the untamed wilds of cheap bullshit. There's little Bioware could have done to make encounter-defining Fighters and Thieves.
A good Fighter in BG2 not only deals out massive damage-per-round, but is either highly-resistant or immune to everything relevant. They might also have a ton of HP and regenerate pretty quickly. This isn't really something that's all that fun to fight on a regular basis, because there's little room for interaction. And when the player wins the encounter, there's the whole issue of the equipment said Fighter was using.
Thieves played well are a great example of something that is fun for the player but would be hellish to play against. Shenanigans with backstabs, traps, and Detect Illusion are all greatly entertaining when you're dishing them out...not so much being on the receiving end. And that's really all Thieves can do to be "good" in combat (well, barring Use Any Item stuffies).
Whereas Mages (and Priests to a lesser degree) can be threatening without being cheap, especially in BG2 where there are tons of ways to interact with, or "go around", the protections mages can utilize. The same can't be said for a good Fighter; can't stop equipment or innate, non-magical, abilities.
Because diverse NPC party vs NPC party battles are pretty interesting? Or in other words, why does it NOT matter?
For one, D&D has an enormous bestiary full of things that can fill the general roles provided by player-classes in any given encounter.
And for party on party skirmishes, I may not have communicated entirely well, brother. Representation and prominence do matter
to a point; having no Fighters in the ranks of enemy parties would be silly. Same with relegating them to the status of mere fodder. But I don't think every class needs anywhere near equal representation nor prominence in party brawls,
as an important principle of design. It's more about the whole machine (encounter) being interesting, rather than any individual part being in a lot of machines.
If anything, BG2 was far more lacking in interesting multi/dual-classed opponents. More Samurai, Lords, Bishops, and Ninja (using Wizardry terms for the hybrids) would be a more pressing concern, I'd think, than affirmative action for Fighters.