There is zero internal synergy with drk burst window and abilities. The only reason to stack buffs and shove everything together is because of external buff windows from other jobs TA, brotherhood, etc. Unload everything you got during raid buff windows, which is good enough. But if you are solo or do not have any notavle raid buffs to center around there is no reason not to just use everything you have as soon as its available, weather its aligned with other drk skills or not.