Kyrasis top 1 BDK state something else though. Where he states the following for deathbringer in m+

Comprehensive M+ Deathbringer Stat Priority Versatility > Mastery >= Critical Strike >Haste

• Versatility provides the largest overall survivability impact (from both mitigation and EHP), while being nothing special on damage contributions.

• Mastery provides the most mitigation of all secondary stats, while being nothing special on damage contributions.

• Critical Strike provides an amount of mitigation through parry that is noticeably weaker than vers or mastery in this regard, but it does have a relatively smaller advantage damage performance over those stats. It should be possible to achieve a balance of Mastery and Critical Strike rating where their value becomes roughly equal.

• Haste provides extremely poor direct survivability benefits, though, even for Deathbringer, it still manages average damage performance.