Hello and thank you Jerseyman and Kronckew for your very interesting postings!
Yes, flexibility of a blade should be optimised.
Too little of it and the blade or arm may break or in the best case throw you out of balance and too much of it would render the blade useless as it won't be able to cut/stab anything because of bending.
Yet, I believe that most of standard European broadsword blades were too stiff for the Pata fighting style.
However, It is possible there were different styles or techniques of fighting adapted to diferent types of blades, but nowdays only the more spectacular swirling style involving extremely flexible (and useless for real combat) blades survived.
