Thomas Shey
Legend
Now this I'm going to disagree with.
Say you want to do a Ticking Clock scenario. The PC's must travel from Point A to Point B or Bad things Will Happen.Looking at the three approaches does highlight the strengths and weaknesses of each one.
In a heavily Sim game, these scenarios don't really work very well. After all, it's mostly just a basic math question. The train leaves at 5:25 traveling at 50 Km/h. Can it reach the next stop, which is 100 km away in under 2 hours? Well, yes. It can. And, in a Sim based game, the DM shouldn't be adding things to the game specifically to slow that train down because that's not really sim anymore. Anything that slows that train down should arise from the setting itself and if there isn't any reason (outside of dramatic tension ones which are off the table) for the train to slow down, then the train doesn't slow down.
Ah, but if you're doing genre emulation, it very much is. There might be a theoretical explanation as to how it works out that way, but its still going to do so, because genre emulation is a fundamentally dramatic conceit. That's what makes it so problematic being balled in with other sorts of Sim.
In old-style Sim you're correct. But GNS Sim isn't just oldstyle Sim.
In a more Gamist game, the question actually changes. It's not Can the PC's arrive in time? No. The question is now, "What resources will it cost to reach the destination on time and will the PC's be able to deal with the challenge at the destination after having spent resources?" It's all about resource management and whatnot. Which in turn, inspires different possible approaches - maybe a sort of gauntlet challenge where the point of play is to make it to the end; or maybe some sort of resource attrition to make the final challenge more challenging. Or some combination of the two. It's entirely possible that the players will never reach the destination, or, may reach the destination too weak to resolve the challenge, or maybe will blow through the entire thing by clever play. It's one long challenge with lots of moving parts.
Not all Gamism is about resource management. Some of it is about proper use of non-consumable abilities and finding ways to apply them to the matter at hand. The only difference between the gamist and dramatist approach here is whether anticlimax is to be avoided; in a heavily gamist approach its accepted, and potentially even considered virtuous.
(Note I did not say narrativist approach, because, again, narrativism is sufficiently specialized I do not feel either competent to or inclined to directly engage with it).