Lady of rain I love you but I have to tell you. In reality no where in time has a professional soldier, general or any man of war ever adopted dual weilding as a serious fighting style, and for good reason. To control 2 weapons, even thin ones at the same time is too dificult that even if you were ambidextrous your concentration would be one weapon or the other, so If you were dueling someone with say One Large sword, they would most definitly win, because in reality all sword swing at the same speed beside them huge fantasy ones. I have at my home a large greatsword, Two twim tantos and one Long sword. Now in this isuation Long sword vs Twin swords, the one using the long sword would proboly stand sideways meaning the only place that the Tanto weilder could reach is their arm.
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And the longswordsaman would most likely win for that advantage on its own.
Now Greatsword versus Twin swords. One strong verticle Cut. Nowhere to run, nothing to do but die, you would need a Larger weapon or a shield to survive.
And if that twin weilder were to go against someone with a shield, they would have no chance. SO basically a second weapon is like a really crapp sharp shield. I for one dont like to use shields but I understand their usefulness.
I hope I didnt offend you.