1. Start Arma 3
2. Go to Editor
3. Place a group of soldiers
4. Select "Group-Icon" and go to "Attributes"
5. Set "Placement Radius to 500
(It works for one group - The group is placed in the given radius)
6. Copy the group (or repeat steps 1.-5.) and paste it
7. Optional: Copy'n a couple more
7. Test Mission: Only one (the last-edited group will be placed in the set radius, all the rest will spawn exactly at position of actual placement)