Should offensive cooldowns stack?
Right now, there is a common complaint in Retribution Paladin circles that Ret burst dps is too high, while Ret sustained dps is too low. One of the major reasons this happens is that Ret can combine at least 3 strong offensive cooldowns together (and then trinkets, potions, etc.). There is a short 20-second window when the burst dps is very high indeed.
As a general rule of thumb, you always want to stack offensive cooldowns together. This is because subsequent cooldowns magnify the effect of the previous cooldowns.
As a simple example, say you do a baseline of 100 dps. Cooldown A increases damage by 20% for 10s, and Cooldown B increases damage by 30% for 10s. If we take a 20s window, we have:
Situation A: Stacking Cooldowns
[10s * 100 d/s * 1.20 * 1.30] + [10s * 100 d/s] = 1560 d + 1000 d = 2560 damageSituation B: Non-Overlapping Cooldowns
[10s * 100 d/s * 1.30] + [10s * 100 d/s * 1.20] = 1300 d + 1200 d = 2500 damage