I've got to say it that if you agree to fight a guy with a sharp piece of steel while you remain unarmed you deserve to be sliced and diced - or at least the guy who negotiated the terms of the duel.
Disarms are not impossible - enough Kenjutsu Koryu include them - but I don't think its the prefered situation no matter how fast you are.
If you are an incrediably fast Aikido shihan then pick up a sword and practice what's necessary. Then you will be fast, capable, and equally armed.