Why standards for top gallantry awards change

Why have the standards for the Medal of Honor and Victoria Cross changed over time?

New lower decorations and changing procedures raised the threshold, so acts once given the top medal might later receive a lesser award.

Early award systems sometimes had a single principal medal for valor, so conduct later recognized at a lower level could receive the top decoration. Adding new grades changed where acts fell in the hierarchy and gradually raised the bar for the Medal of Honor and Victoria Cross. During the Falklands War, tight submission deadlines and other bureaucratic rules affected nominations. The Royal Navy regarded bomb-disposal work under continuing air attack as service in the face of the enemy, supporting a case for a high gallantry award. Mine-clearance and bomb-disposal personnel whom the Navy wanted to recognize received mentions in dispatches instead.