What would you prefer for battles? Better Units or better Heroes or both?

[Renevent]

What I would think would be cool is more hero skills that open up unit tactical options.

For instance, warrior skill line that has skills that give all units categorized as archers a 'volley' skill, or all units with swords some bleed skill.

Mage skill line could have stuff to grant magic units extra abilities as well.

I think there's a lot more that can be done with the hero's advancement and how it effects things on the battlefield.