The reason for this is because in very early WoW paladins had Crusader Strike and Holy Strike - the same 2 abilities that Scarlet Gallants and Champions have. However, they made paladins way too OP (Crusader Strike increased holy damage taken, Holy Strike dealt ~200% weapon dmg as holy damage), and so Blizzard decided to remove them altogether. A while after this video was out Paladins got Hammer of Wrath in Patch 1.7.0 (2005-09-13)