Given what we've seen from the best parses so far, we can pretty readily expect Deadly to continue being one of the most used sets in the game. With the synergy it has with Fatecarver and the additive properties of Necro subclassing, it's going to be an auto slot option in just about any content. Add in the fact that it has better small stat lines and doesn't have the limitation of being 'done to monsters', is there any reason the 5 piece for Tide-Born can't also be 15%? It's not like either set is even remotely difficult to acquire, so surely there's no reason to pretend that one should be held in higher regard than the other.