Why does Clemency get interrupted? And why does Sword/Shield Oath reset combo?

[Galactimus]

While it's not a perfect solution you don't always have to switch to Sword Oath to increase your DPS.

You can simply remove Shield Oath, which doesn't use up your GCD, does not break your current combo, and removes the 20% damage penalty that Shield Oath was giving you. Being in this Oathless state is great for when you need to push that extra bit of damage without forcing yourself into another clunky oath.

Short term its a huge dps gain. Let's you finish your next couple combos with an extra 20% damage without losing your combo or a GCD.

Long-term it's a dps loss. Not being in Sword Oath for an extended period of time will eventually negate the bonus damage you did while Oathless. However this allows you to activate an Oath at a much better time (ie. when it won't break your combo, during phase transitions, etc.)