Need help rotating multiple paths on an axis

I am building an RTS game similar to Age of Empires 3, and I've hit a wall. I have a for loop that sets the path of all your selected units, and then spaces them out evenly into a grid formation. (Here is the code)

         int maxColumns = 5;
         float spacing = 1.5f;
         int height = 0;
         int width = 0;
         int objectCount = selectedObjects.Count;
         for (int i = 0; i < selectedObjects.Count; i++) {
             Vector3 location = hit.point + new Vector3 (width * spacing, 0, height * spacing);
             selectedObjects [i].GetComponent<NavMeshAgent> ().SetDestination (location);
             width++;
             if (width == maxColumns) {
                 width = 0;
                 height++;
             }
         }

Now this code will move my units into a grid at the spot that you commanded them to go to on the map, like this.

Now this is great, however I need these paths to move in a square formation that isn't always aligned straight up and down, but rather rotates based on what direction they are walking towards. (Like this)

Any help on this would be appreciated!