While sho is up, yes, halone is useless, but if you swo, halone is a must every 4th combo.

For holy spirit' damage you accumulated damage aggro after the damage is done, not during the casttime, if someone else is good at dpsing can steal it.

seriously when the red icon in agrgro list starts to blink should halone, just for safety, no one will use their aggro management role skill in 4men.