Why does Ezio have matching vambraces on the cover but not in the game on assassins creed brotherhood

Hi At the beginning before the villa attack you have matching vambraces and 2 hidden blades but after the attack a cannonball breaks a vambrace and blade so you only have one of each. Later in the game you meet leonardo de vinche which you can purchase a second hidden blade again and at any blacksmith after you have the hidden blade you can purchase the second vambrace again but when only you have the second hidden blade.