Complex sentence: The main element of 3 Commando Brigade was not deployed in the 1991 Gulf War except for 24 men from K Company 42 Commando Royal Marines who were deployed as six man teams aboard two Royal Navy frigates and two Royal Navy destroyers.
Split into simpler sentences: The main element of 3 Commando Brigade was not deployed in the 1991 Gulf War. However, 24 men from K Company, 42 Commando Royal Marines were deployed as six man teams aboard two Royal Navy frigates and two Royal Navy destroyers.