If I look back what I've already try to do with SoapUI, I would say no.
Let me explain: once I tried to do some similar thing and what hurts is that updating variables can lead to change previous or future execution, resulting in similar cases.
What you're excepting is to do some kind of multithreading or asynchrone executions.
In both cases, you should consider doing this only with code.
And to go further, may be not even with SoapUI (don't know if Groovy is the best langage for doing this).
Tell us what you think about and what choice you'll make.
David.
