Such a good post until you got here lol.
First off, we're not talking about the modern day. And historically, it's absolutely fair to say that, it's particularly fair pre-1700 or so. In fact, pre-1700, it's probably an understatement.
But I nearly put in a caveat saying "obviously this doesn't apply to modern-day or recent past soldiers who have to stand guard as part of their duties" (same for police who have to do that too). But I thought "Naaaah, no-one is actually going to think that it does, because obviously we're not talking modern-style soldiers in most D&D heists, we're talking 1300s to 1600s hired help and low-INT monstrous humanoids". Apparently I overestimated the audience's desire to read generously there, in a sense. I guess the old adage is true.
But yeah, I don't mean modern-day soldiers or police because I'm talking about a D&D setting, not, like, your local military base or bank or w/e. Actual soldiers don't have the "embarrassment" factor either, because it's more embarrassing to not follow protocol than it is to "cry wolf", so that yeah a level of discipline like, say, modern-day US soldiers would make a heist near-impossible unless it was pure deception of a kind that relied on the machine working itself.
If you're running D&D like the sort of guys hired to guard a counting house or whatever are disciplined and highly-trained US soldiers (which even pretty basic recruits are today), with an extremely well-developed set of protocols and methodologies, a perfect chain of command, and so on, well, I think obviously then it's going to be real tough for anyone going up against that. I wouldn't do that myself. They're people who've been hired to stand around all day and look threatening. It's likely they're from various backgrounds, not well-disciplined (few armies were, and they're not an army), that they probably don't have any espirt de corps, bored, not necessarily very bright, and to have picked a job which doesn't involve them doing much work, and likely does mean they get to push some people around (just not the rich ones).
Anyway, ignoring those shenanigans, I actually agree that adventure has pretty bad guidance. I don't agree that means you have to take a catastrophist approach because of how one adventure is written, nor that it demands a catastrophist approach, but it's bad guidance, I can't disagree.