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If attack equals, toughness, attacker wins.

But this was not the case here

It was.

Attacker 4 Strength, Defender 4 Toughness.

Oh, now I got it. And all the other parameters in which I was better don´t count? That is a little one-sided.

They do count for other things. You had a 5% chance to intercept due to your speed vs their tactics. They had a 0% chance to crit you due to your leadership vs their morale.