They’re based on real techniques. The sword technique is based off of Wushu sword forms (albeit the swords in question differ in shape and application), the arcing swings are very prevalent in Wushu sword performance forms. Not necessarily combat forms.
If you must know, I’ve got a Chinese Martial arts background of…

Good luck pulling your gun out, undoing the safety, cocking it, and then aiming it whilst I’m punching your face in.
LOL @ the idea of bringing a gun to a fist fight.