If you mean "there's lots of weird, inconsistent rules which make it hard to state anything categorically about AD&D" then I'd agree, but I don't think it invalidates the wider point. YMMV.
And I don't disagree with this either. I'm pointing out that some people like a predictable, shared mechanical model for their PCs and NPCs. And that such a model is frequently - albeit inconsistently - employed in AD&D.
Honestly, I'm having trouble understanding why stating the case for NPCs often using the same mechanisms as PCs in AD&D is receiving such pushback. It seems fairly self-evident to me.
What I would like to have happen in conversations about these kinds of things (PC : NPC build symmetry or not) is brutal clarity on why one might want this and why one might not want this. Here is how I would assess:
*
Challenge-prioritizing play doesn't require PC : NPC build symmetry. Some games that feature intense, and intensely compelling/functional, challenge-based decision-spaces are composed of engines that feature PC : NPC build symmetry while others that are preoccupied with the same challenge-based priorities see their engines having quite different approaches to PC : NPC build.
So its not challenge-based priorities and engine functionality that is the pivot point here.
* Any
storytelling imperatives a game might undertake (regardless of how distinct those agendas and individual game engines are from one another) are totally detached from PC : NPC build symmetry. Its an irrelevant decision-point at the design level because incentive structures, authority distribution, adancement/reward cycles, and the various widgets/levers/currency inherent to the resolution scheme are entirely insensitive to PC : NPC build symmetry.
* Here is what I think it comes down to (which is where I think a lot of these conversations land);
a certain cognitive orientation to immersion. There is
a cohort of players out there (I'm not interested in the scale of them)
that have their immersion priorities very much anchored to processes' role in generating content. It might be something like "well the basic biological substrate and evolutionary pressures inherent to creature A is no different than that of creature B in our material world...so we really need to model this in our fantasy game engine or my brain is going to be constantly drawn to the artifice and conventions of
game...ergo my immersion goes kersplat."
That is absolutely a thing. And I wish we would be clear about that, while simultaneously being clear that "this is not the only way to skin the immersion cat...its just your cognitive system's unique demands." Further still, I wish we would be clear about the tradeoffs of such design imperatives. There are virtually always tradeoffs here. PC : NPC build symmetry might cause prep time or table handling time for in-situ content generation or action resolution to increase. Focus on granular, symmetric process might dilute or detract from (perhaps because it makes it more difficult to generate or apply via straight application of the rules) situation-framing or consequences that focus on metaphor, motif, symbolism, genre conceit, emotions, or the internal workings of something/someone. Focus on process rather than outcome might make conflict opposition rostering/budgeting more difficult both in the GM's generation of the content via system (more overhead, more administrative work, more table time in the handling) and in the process and outcomes of the play precisely because it isn't outcome-based (where outcome-based design can first order aim for target difficulties and dynamics, process has those target difficulties and dynamics as second order...because the first order is
hew to process). Finally, a few of these trade-offs together (or all of them bundled) will inevitably lead to a game that is deeply pre-play prep intensive for a GM (with all of the implications of such prep upon play) vs one that can be mostly GMed with relatively sparse prep but rigorous structure/tools for quickly generating content in real time.
So someone with this particular cognitive orientation toward immersion and this particular brand of immersionist priorities will likely want the sort of process-based game engines that are the archetype for PC : NPC symmetry (note that there are some exceptions both ways...some outcome-based engines have significant, but not wholly, PC : NPC build symmetry; Torchbearer). However, that is kind of the start of the conversation rather than the end of it...because
now we're talking about the fairly sizable tradeoffs between process-based game engines and outcome-based game engines.