The missing man formation, to me, has the same kind of significance as a state funeral for a president. I remember seeing President Kennedy's funeral procession. The riderless horse had the boots turned backward in the stirrups. That was so eloquent and illustrated so well the significance of the whole procession.
I remember seeing a film of Martin Luther King's funeral procession, and his coffin was carried in a mule-drawn wagon. I thought that was a beautiful reminder of how he began, and that he was true to those roots, in spite of the fame he achieved.