f you're having trouble with the enmity, just go ahead and do a couple more Rage of Halone combos before swapping stances just to make sure.
Yeah, unfortunately I don't always know I'm going to have a problem with Enmity until after I'm already in Sword Oath, and I see that the DPS is overtaking me. It's usually when the boss is at about 30% health or so. What I end up doing in those fights is either staying in Sword and going Goring/Halone/Halone/Halone/Goring, or switching back to Shield for the remainder of the fight.