For example, if the teams are having trouble developing any kind of story at all, or one that doesn’t seem to respect the boundaries between the scenarios, mixing elements from different scenarios instead of crisply sticking to the parameters as defined, it could be because the two critical uncertainties that were chosen are too vague, or perhaps the binary aspect is not clear enough; the either is too much like the or.
The problem could also be that there is too close a relationship between the two critical uncertainties.
They need to be independent of each other; if they tend to move together, both up or both down, or if uncertainty 1 causes uncertainty 2, then go back to the drawing board and define a new pair