Defense or Attack STATS?

[Divinus Arma]

2hp units are better when assaulting stone walls when not number of soliders, but quality of individuals counts more.

That makes sense. But then which is better for holding the walls: high att/low def or low att/high def. Similarly, which is better for taking the walls?

I would imagine that a high def would be more important in taking the walls, simply because they need the oppoprtunity to stay alive to try to attack. They cant attack if their dead... Hmmmm, in that case, maybe high def is better in all circumstances, unless you are flanking/surrounding.