" it worked so well, that the to opponents were not able to hit each other."

LOOOOOL!
that'd be great... a game where you can't hit each other because your fighting and blocking skills are perfect ... I think those ppl would all turn into pazifist pretty soon, getting tired of fighting ^^

I'd very much like to see a demo of both your projects... if possible...
The approach you're doing, Shore, does not leave as much room for the user's skill though.. if your block is always the right one. What I'd do is combining the two. Checking the state rather than collision detection can be a lot easier but maybe look unrealistic. (you need to stop the animation at exactly the right time, right? and how does it work if the two don't stand exactly infront of each other? That wouldn't work at all)...
For example: if you atttack from behind, and you use attack animation 1, the opponent uses block animation 1 that corresponds to attack animation 1, but he's facing the other way, so your sword stops in mid air because he blocked in the other direction? Maybe checking state to determine the reaction and then preforming collision detection to see if the reaction was any use at all would work together better??