How to issue many orders to Fighting unit at once?

[WC3Wonderer]

1. Paladin and four swordmen stand in the forest.
2. Paladin has Holy Light.
3. Holy Light has no cooldown.
4. Ten ghouls attack Paladin and four swordsmen.
5. I order Palading to cast Holy Light spell on four swordsmen while holding shift key.
6. Palading keep smashing ghoul with his hammer.
7. Palading kills ghoul and casts Holy Light on four swordsmen.

Palading must execute orders immediately. Why Paladin keep smashing ghoul? How to issue many orders to Fighting unit at once?

 

[Chaosium]

You need to use the 1st holy light without holding shift otherwise the unit waits until his current order is done before using the spell

 

[WC3Wonderer]

I order to cast Holy Light without shift key. Palading casting Holy Light. I order to cast second Holy Light holding shift key. In tiny period of time After first order and Before second order my Palading attacked ghoul. Palding keep smashing ghoul and refuses to cast second Holy Light.

 

[the.Axolotl]

This happens because there’s a small gap between queued orders where the unit becomes idle for a frame. During that frame, the Paladin auto acquires a target and starts attacking. Since attack orders are sticky, they take priority over queued spell orders, so the unit keeps attacking instead of casting.