The requirement is to implement Control group on a proposition level.
To illustrate, each proposition will be having it's own control group so that specific propositions will not be shown to that group. Pega OOTB offers control group on a segment level, catering to all propositions, which is not the requirement here.
Also, this needs to cater to both inbound as well as outbound interactions.
Can I use any random number generation method to do this?
Are you having anything in mind as to how I can get a consistent assignment per proposition per interaction? Even if I do a random number generator function,how will I ensure that the random numbers are consistent for e.g. approximately 10 out of 100 times, the number will be from 1 to 10 (considering the percentage provided for a particular proposition is 10%). Is there a way to smooth the number so that this becomes consistent?