Why can't you use volume constraints? Please elaborate on your reference to randomization being the reason.
You shared a picture of a strategy that evaluates some offers for a customer (remember strategies evaluate customer at a time). What do you expect to happen next? Asked in another way, what is your business requirement? What is the business outcome you that you want to achieve?
The randomization will happen in the strategy and will split your eligible customers into those customer that will get an offer and those that don’t. For those that do get the offer, Volume constraints will do any limit caps you need. What is it that you think you are missing...reporting of some kind?