So, firstly that 'double bladed sword' is completely pointless, it doesn't even have the reach of a bo staff, secondly it's made by united cutlery which are renowned for making things that look really cool and sound really cool and are entirely fictional and not actually made to any standard (420 steel is kinda pants, most swords made for actual use by western martial arts are 1060 and up).
on the sai, they may be traditional (I'm not up on my Japanese weaponry) but that guys 'techniques' are kinda stupid. if I've got a guy trying to strangle me and I have a stabbing implement, it's going straight into his eye or his throat. I'm also pretty sure in the western late medieval period they had similar things which were called
Parrying Daggers
That mace is also kinda a movie prop, but
Flails are a thing and have their uses.
on the other hand, bows, and spears really were the workhorses of war for most of history and I'd love to see those, and for all you Japanfans out there
Naginata and equivilents (doesn't that Naginata look suspiciously like one of
these)