Little One, in 3.0, reloading an arrow doesn't cost a turn. Therefore, at the beginning of the battle, I charge an arrow with Meteor Shower. And then, either with Shock or Freezing Cold.
Probably, even when upgrading light magic, you can charge an arrow with Divine Vengeance. But for it to work, the enemy must deserve it. And Chaos can deprive him of this opportunity. Especially if Empathy is upgraded.
Recently, while playing through a campaign, my hero with Empathy always went before all the enemy units and heroes - necromancers.