The latest versions of everything all have the same spreads (1–2 disaster, 3–4 setback, 5+ success), so you may be looking at an older version of Inner System Blues. The original spread was inspired by the luck roll in Electric Bastionland (which doesn't lead to many interesting disasters even when unskilled). I also tested with the Blades in the Dark spread (1–3 disaster, 4–5 setback, 6+ success), which felt like more of a downer than intended. I recorded all the dice results folks rolled and found that if we'd been using the spread I have in there now, it would've been about 70% "I get at least some of what I want," which was around what I was shooting for.
Nice! I agree that the original spread in EB was too forgiving for my tastes… Blades in the Dark can have the opposite specifically because players can choose to resist consequences, and in any case often those consequences are “tick a clock”, not always immediate.
Apparently I just have an older copy… thanks for the answer!