Executioner is good on lower armor opponents, and generates more rage per white hit, and increases yellow damage.
Mongoose is crit and dodge, and crit is nerfed in the higher levels of arena by resilience. Dodge for a pvp warrior is kinda mediocre.
Savagery is a solid enchant too. More rage per white hit and increased yellow damage, but it's a little behind the curve when compared to executioner.