One object joining 9 others to complete a triangular formation.

The date is approximate.  I saw the report from millington on this date and I remember something very similar.  Myself, my brother, 2 cousins and a friend were sleeping out in the back yard and were looking at a bright clear night sky.  I was about 11 years old.  I first saw a triangular formation of 9 crafts, red in color moving from south to north.  No blinking lights noted.  Was constant color of red.  To traverse the whole sky took about 1 hour.  As we watched, the formation looked like a rack of balls on a pool table missing the 1 ball at the front.  From nowhere, a single craft started moving toward the formation of 9.  That formation stopped, then one left that formation to join up with the single.  It looked like they were going to collide.  They did not.  These two, joined the others, and became a complete formation with the one joining at the front to complete it and continue across the sky.  We watched till they traversed across the whole sky to the northern horizon.
 A note on my experience, I am ex USAF.  I have been in the aircraft industry for over 20 years professionally and still employed in the aircraft industry.  Am very familiar with all aircraft and flight dynamics.  I have studied flight since I was about 10 years old.  I know how aircraft act along with rotor craft.  This formation was way too high for that and NO sound was noted.
Date is approximate.  PD