Just looking at this: players assemble modifiers in all sorts of way.The first process I looked at was the stochastic method. My framing is that the function of the stochastic method is to choose between possible subsequent worlds. When we're about to roll, multiple worlds are possible. Once the dice have fallen, we'll agree on one world. RNG is the die. P captures the modifiers player has assembled. World captures the game world parameters (AC, DC etc.)
RNG + P + W
RNG + P
In MHRP/Cortex+ Heroic, all rolls made by the players are opposed, either by another acting character or by the Doom Pool. All outcomes are rated by size. One outcome can be stepping back a trait on one's own sheet (eg injury) or on another's sheet (eg ripping off bits of Iron Man's armour).
Suppose that player A's PC rips bits of Iron Man's armour (say with a successful check against Iron Man that draws on a combination of Strength and Technical expertise (maybe Bill Foster is doing this in his Goliath form); and the player B's PC has an easier time beating up Iron Man as a result. Is that P, or W?
A parallel thing in D&D might be one PC grabbing a character and a second PC taking advantage of the immobilisation to beat the character up.
A game in which augments/bonuses are gated behind successful actions (be they helping actions from others, or one's own "auxiliary" actions) will have a different feel from one in which a player can accrue them without having to perform an action (especially when, as in MHRP, there is an action economy).
The same is true for one where augments/bonuses are available by spending currency (eg in Fate, paying a fate point and then narrating post facto the W) vs one where the fiction serves as a constraint, because it is already established prior to the check being made.
I also don't understand what clarity is gained by replacing Baker's notion of negotiated imagination, which requires decisions (perhaps mediated by dice rolls) as to whose preferred imaginative content is introduced into the shared fiction, with a notion of "possible worlds".