Most of single scenarios has some element of randomness in the set up phase. My playtesters are always surprised with my love to shaking things up, to see unexpected, to throw things and see where they landed.
It's a pain for playtesting. Instead of pre-constructed set up, instead of preparing everything upfront I just give you few toys and say: 'Roll them and see what happens'
Sometimes scenario is easier than I expected. Sometimes is harder than I planned. But it most cases it is different. You sit, you look at the board and say: 'Huh, that's new. How should we approach this mess now...'
In each scenario you find tools to manage the luck. In each scenario you have a dozen of ways to 'Science the shit out of this.'
But before you start science it, I'll ask you to throw the box in the air and see what happened, when it lands.