From manual:
So, first step is to set the group to start from ramp, then check "uncontrolled".
Next step is to click on "Triggered Actions" (next to payload), choose "Set Option" (or "Perform Command" - i'm not at my PC right now, just search START command) and click "Start".
In the new panel you will have the field "Name" - set something like this: "my AI division start event".
Then go to triggers, set trigger to ONCE, condition to time more - 600 seconds (do a test first and set it to 10 seconds, no need to wait 10 minutes) and actions to task set - click the drop-down and choose "START - my AI division start event".
Finally, check again if "uncontrolled" is set, sometimes it is unchecked by itself.