System mastery is one manifestation of "step on up"
as Edwards uses that phrase. To quote:
[Gamism] operates at two levels: the real, social people and the imaginative, in-game situation.
1. The players, armed with their understanding of the game and their strategic acumen, have to Step On Up. Step On Up requires strategizing, guts, and performance from the real people in the real world. This is the inherent "meaning" or agenda of Gamist play (analogous to the Dream in Simulationist play).
Gamist play, socially speaking, demands performance with risk, conducted and perceived by the people at the table. What's actually at risk can vary - for this level, though, it must be a social, real-people thing, usually a minor amount of recognition or esteem. The commitment to, or willingness to accept this risk is the key - it's analogous to committing to the sincerity of The Dream for Simulationist play. This is the whole core of the essay, that such a commitment is fun and perfectly viable for role-playing, just as it's viable for nearly any other sphere of human activity.
2. The in-game characters, armed with their skills, priorities, and so on, have to face a Challenge, which is to say, a specific Situation in the imaginary game-world. Challenge is about the strategizing, guts, and performance of the characters in this imaginary game-world.
For the characters, it's a risky situation in the game-world; in addition to that all-important risk, it can be as fabulous, elaborate, and thematic as any other sort of role-playing. Challenge is merely plain old Situation - it only gets a new name because of the necessary attention it must receive in Gamist play. Strategizing in and among the Challenge is the material, or arena, for whatever brand of Step On Up is operating.
In the essay, he goes on to discuss the extent to which competition can be high or low at level 1, or level 2, or both, or neither. The following summarises rather than quotes:
*High competition among players, but not PCs, is team-based play with individual XP or other rewards (some classic D&D; Agon 2e);
*Low competition among players, but high among PCs, would be low-stakes intra-party scheming play (perhaps some Paranoia?);
*Both low would be team-based play with group XP or similar (eg some classic D&D tournament play, or a similar approach to a modern AP);
*Both high is competition among the PCs that translates into genuine competition among players, analogous to a wargame but via the RPG vehicle - a lot of D&Ders would see this as pretty munchkin-y stuff, I think.
I think Torchbearer is either the first or the third, depending on how much competition there is among the players to collect advancement ticks and earn Fate and Persona (especially MVP).
The essay also distinguishes between "the gamble" and "the crunch". To quote again:
The Gamble occurs when the player's ability to manipulate the odds or clarify unknowns is seriously limited. "Hold your nose and jump!" is its battle-cry. Running a first-level character in all forms of D&D is a Gamble; all of Ninja Burger play is a Gamble. More locally, imagine a crucial charge made by a fighter character toward a dragon - his goal is to distract it from the other character's coordinated attack, and he's the only one whose hit points are sufficient to survive half its flame-blast. Will he make the saving roll? If he doesn't, he dies. Go!
The Crunch occurs when system-based strategy makes a big difference, either because the Fortune methods involved are predictable (e.g. probabilities on a single-die roll), or because effects are reliably additive or cancelling (e.g. Feats, spells). Gamist-heavy Champions play with powerful characters is very much about the Crunch. The villain's move occurs early in Phase 3; if the speed-guy saves his action from Phase 2 into Phase 3 to pre-empt that action, and if the brick-guy's punch late on Phase 3 can be enhanced first by the psionic-guy's augmenting power if he Pushes the power, then we can double-team the villain before he can kill the hostage.
The distinction between Gamble and Crunch isn't quite the same as "randomness;" it has more to do with options and consequences. Fortune can be involved in both of them, and it doesn't have to be involved in either (see Diplomacy for a non-RPG example).
Torchbearer strongly leans towards Crunch. So does 4e D&D combat.
I wasn't there, and so can only make informed conjectures about your TB2e play. My default conjecture would be that your experience of both gamist and simulationist play is more likely to be the sort of shift that Edwards describes. For instance, in a conflict it is probably gamist priorities, with some colour overlay drawn from Beliefs, Goals, etc; but then when it comes time to negotiate a compromise that colour gets prioritised in a more narrativist fashion.
But your experience may belie my conjecture!