The worst run of luck I've had was spawning 12 of the wrong tier in a row (although that isn't the norm), and that is before you then get into the "which of the crimes in the correct tier will it actually give me".
We haven't run out of scope (yet) but came close a couple of times - if RNG had also cursed us with a cluster of failed OCs at those times we could have done though. And that was without us skipping any "trash" OCs.
I am more annoyed by the combination of not having an easy way to see which faction members are suitable for each scenario/role and no way of reserving/restricting spots for suitable players - spawned an OC which isn't suitable for anyone right now and will despawn before they finish their current OC? Tough luck. If they are going to leave it as this "grouped RNG" spawn instead of more control, then simply having them manually despawnable (with just a 1 scope refund) and not automatically vanishing would help both situations.