The game manual that comes with the Xbox 360 version says. "... so you and your partner will overwhelm the enemy, complete successful missions, and become an Army of Two™." The only reason I can think of it being called "Army of TWO" is ~SPOILER FOLLOWING~ Salem and Rios start a PMC at the end of the game called Trans World Operations(TWO), displaying them in gear bearing the logo "TWO". ~END SPOILER~

Also, since the title of the game is Army of Two(not Army of 2), it should be known as "AoT", not "Ao2". ~  (contribs)