Having re-read the PDF a bit more closely, I'd have to say it's less about the danger of Guts rolls (though that's part of it) and much more the other thing - each of the three attributes are slightly asymmetrical. Guts rolls have the capacity to directly impact Efficiency, either through sabotage or by surprising or flustering the System, but can result in tangible physical harm, and are thus best to avoid, if possible, until the Subjects have at least a semblance of a plan - that is, if a group is interested in playing "strategically" as opposed to playing purely for storytelling purposes. Drive rolls are largely reactive / defensive, and carry the long term risk of psychological dissolution. As such, it's almost like Guts are the "attack" attribute and Drive is the "defense" attribute. Guile rolls are the default when it comes to preparing for a break-out attempt. It is almost always going to be "optimal" to engage with the System using Guile until a more direct strike is either necessary or most opportune.
I think the fact that most rolls don't determine what happens but rather how the system responds is another important distinction. In most cases, players get to decide when they've earned a secret. The only requisite for doing so is the acquisition and interpretation of new information, and the only requisite for that is action. It ultimately doesn't matter if the person a PC is questioning, whether through subtlety or force, tells them everything they know, because it's just as valid to draw conclusions from what they aren't saying, what they're leaving out or lying about, as it is to take them at their word. As such how an action plays out can reflect the way a dice roll falls, but it's mostly a matter of roleplaying. A failed Guile roll, fundamentally, means that the System notices anomalous behavior (the player can still gain some information and even claim a secret in the process), and a failed Guts roll means that the system retaliates (or makes a note to do so in the future) in kind. Similarly, when the System forces a Subject into making a Drive roll, the Subject is not obligated to actually fail at resisting their directives / temptations / etc. They can still choose to say no, for roleplaying purposes. What the failed roll indicates is that their overall relationship to the system, at least in that moment, has shifted somewhat - the experience unbalances them and forces them to doubt themselves, experiences fear, etc.
If I were to do a "second edition" rewrite, which ... who knows, I might, now that I'm thinking about this game again, I'd probably clarify the ruleset a bit more, and probably append a few additional mechanics (also, fix the typos, or as many as I can catch ... there are too many typos). For one, it occurs to me that a "reset" mechanic might benefit certain kinds of play: instead of killing or permanently disabling the Subjects, a devastating enough loss / "TPK" might result in a somewhat dreamlike reassertion of the status quo - the Subjects wake up to a new day, with their attributes reset, and possibly even reassigned, and may or may not remember what has gone before. Vigilance may begin a step higher than the last time and Efficiency damage may or may not be entirely repaired (perhaps the System would have to roll to determine the extent to which it was able to "heal" itself while the Subjects slept). Things might be subtly different. Perhaps there's now a watchtower in the middle of the island where there wasn't one before. Perhaps the NPCs are all entirely different, or the same people playing different roles. I don't know, I figure there is a high enough likelihood of failure - might as well make it more interesting. Plus, the cyclical / looping thing would be more in line with the source material.
Anyway, sorry. Your question just got me thinking about this game again, after a long time, so I'm mostly dumping all my thoughts out here, while I still have them running through my head.
Viewing post in Is guile meant to have no mechanical effects?
Gotcha gotcha. I think it’s the name of Guts and Guile that threw me off then, because it kind of frames them as more skills, or the mindset with which the players attempt an action, which kinda led me to wonder if “subtly poisoning NPCs against the System” should trigger an efficiency roll with guile without using guts, since it wasn’t a forceful action. I guess that would probably require both rolls then.
Anyways, thanks for the quick response, I’m running a oneshot of it in a few minutes haha.
Makes sense. I suppose one way to think about it is that these are qualities which are being tested by a given situation or action, as opposed to innate skills or qualities unique to a PC. I think in the example you'd described, I'd have probably also ruled that both Guts and Guile would have to be rolled, the first as a representation of the resolve / nerve / courage it takes to directly oppose the System in a way that might harm it, and the second as a means of deciding whether the Subject in question gets found out in the process, or otherwise manages to raise any red flags. It's all abstract and interpretive, of course.
In any case, thanks for playing! I hope your session went well.