Sorry, but this is simply not how fights work. There are hundreds of thousands of variables. How much is each of them trying. Where are they fighting. Are both of them in top health. But most importantly, you are never going to get two swordsman with identical capabilities. Even if they practice the same style, they'll differ in the nuances of their techniques. By necessity, the two people will be doing different things, not mirroring each other, because if one performs A, then the other will have to try and find a way to counter it with B, which the other will be trying to anticipate with C. The airbendiing grandmaster swordsman is more likely to win, sure. But will win? You can never, ever assure that. In a fight, the smallest of things can mean the most colossal of differences.
It's a contentious topic because if bending worked the way you suggested it does, then the White Lotus' assault on Ba Sing Se would have been a hilarious failure, unless your suggesting that those 5 old farts literally have more skill and power than an entire army empowered to 10 times their strength by a comet while in a strategically defensible position.