Is there a more efficient way to stagger emails over a few days using the Microsoft Attack Simulator?

Question

I wanted to know if there is a more efficient way to stagger emails over a few days using the Microsoft Attack Simulator. According to Microsoft, we would have to divide our target list into multiple groups and hit those groups on different dates. The idea is to send a phishing email test to all employees but in a staggered fashion, so that it isn't clear it's a test.