ummm...look at the wikipedia snippet from the MASTER CHIEF article... "In addition to the five Spartans mentioned above, there are in fact three other Spartans who were otherwise engaged on fields of combat too distant to be easily recalled, when the Spartans were gathered on the Pillar of Autumn, prior to the fall of Reach and the events on Installation 04. They may have since fallen to Covenant forces, or are currently en route to Earth (though the former is more likely)." Hmm....how many SPARTANs are on the cover? Three.