Retribution has a troubling issue of lack of reliability in it's DPS output. I do have a suggested fix for Art of War and Divine Purpose's Unreliability.
Art of War
Your Censure has a 4.4/8.8/13.2% chance per stack per tick and your Seal of Righteous (if it hits atleast 3 targets), has a 10/20/30% per hit to Grant Art of War. Art of War cannot occur more than once every X seconds.
X seconds would be the balancing factor to how often this effect can activate. Instead of waiting for the proc, the proc is highly likely to occur but not at the start of battle, not tied to Holy Power and It has a reliable chance to appear without it being spammed with abuse.
The only issue that surrounds this is that it can be used to kite melee classes, but also allows Paladins to chase those who would kite aswell. Censure can be applied from Judgement which can supply mana, increase movement and can be casted from up to 30 yards away. This gives the Paladin the ability to have it's own method of Tracking instead of Catching Up.
Divine Purpose
Divine Purpose can proc from almost anything, which makes it very unpredictable. The chance of proccing should increase but narrowed. Now here two birds can be killed with one stone. What other ability (other than concentration) that can be used in our rotation that is basically almost pointless other than dealing extra numbers? Holy Wrath. The name fits?
The talent would as read;
Reduces the cooldown of your Holy Wrath by 2.5/5seconds. When you cast Holy Wrath, you have a 35/70% chance to gain Divine Purpose.
Here is my suggests to a bit more RnG control. The RnG does make the class feel more special than it once did, the suggests make more spells feel relevant. As for Consecration, Holy Power ability