Paladin tanks have threat generating skills that line up very nicely in a rotation of 9 second cool down followed by 6 second cool down followed by 9second cool down etc.

example stolen from first google'd post i ran across:
Holy Shield (9 second CD)
Hammer of the Righteous (6 second CD)
Judgement (9 second CD)
Shield of the Righteous (6 second CD)
Concecration (9 second CD)
Hammer of the Righteous (6 second CD)
Holy Shield (9 second CD)
Shield of the Righteous (6 second CD)
Judgement (9 second CD)
Hammer of the Righteous (6 second CD)
Concecration (9 second CD)
Shield of the Righteous (6 second CD)