I don't suppose we've cracked the battle engine enough to know what all those stats do yet?

The modifiers would, I guess, be added to the attack.

"Skill" and "cooldown" in particular seem mysterious.

In MTW, I understood the units took turns hacking at each other with some probability of death based on attack-defense +/- modifiers, but I've heard it mentioned that in RTW units attack at different speeds.