Macca's on the right track, but for the second trigger I suggest this:
Trigger2Activation: Radio Beta
On Activation: "_x dofollow (leader _x)" forEach stopArray; hint "Moving out"; 2 setRadioMsg "null"; 1 setRadioMsg "All groups stop"
The dofollow command effectively tells the guys to 'get back in formation', and to move to their current waypoint.
Do move will tell them all to move to that specific position. The same as "2, move to tree, 3 o'clock" etc. So they would move as individuals, rather than as a group
Try that and see how you go.