How to assure a fixed number of raters per scenario

Hi all,
I have around 100 scenarios that need to be read and by the respondents. Ideally, each scenario will have exactly 2 respondents reading it and answering questions about it. I have multiple questions regarding this setting:
1) Let's say that I randomly assign participants to the 100 scenarios using randomizer or questions randomization, and then set a quota of 2 for each scenario. When this quota is met - does it affect the randomization? I mean - does the randomization algorithm considers already-met-quotas as scenarios that should not be assigned to participants?
2) If this method is the right way to go - how do I create the 100 quotas at the same time?
If there's any other way to assure a fixed number of participants for each scenario - I'd be happy to hear!
Thanks!