This card might be hard to pull off (due to the high cost and Trait restriction) but when it comes online it's really a thing of beauty. Not having to worry too much to handle defenses but also having to attack and kill some enemies later, but having the freedom to fully commit to attacking is quite liberatory. It can be combined with The Hammer-stroke (and possibily Hour of Wrath + Éowyn) to better cover the combat across the table. In that case some Good Meal help might be needed, maybe in a Éowyn / Merry deck (or even a MotK Pippin)
Sure Thicket of Spears is an alternative but they fulfill different objectives (and have different restrictions to keep in mind), the main difference being that Oath of Eorl might let you destroy an immune enemy before it attacks, while Feint and Thicket of Spears cannot.