The pirouettes and other acrobatics are from the books.
That doesn't make them less retarded. Ok I get he is a Witcher he is super fast so piroutte doesn't put him in danger like it would with the a normal human. But imagine how much faster he would've been if he didn't use it at all.
In books this move was used mainly when witcher couldn't predict enemy strike from his body movement and he wanted enemy to do something. So he did half spins and pirouettes to make enemy do something either attack or change position. Him doing pirouette gave enemy chance to predict witcher movement and attack him as no human could just stop and strike in counter to his body spin. Problem is that he was witcher and in books he often won fights because he didn't use natural body movements like you would in real life. He didn't "chain combos" He instead used his witcher body to move faster and overpower gravity of his sword to strike from positions in which his body movement was in opposition to his strike.
Basically he simply overpowered with his body mass of sword moving fast and strike from unexpected angles even by experienced fighters.
This is also why he was able to fight multiple enemies.
Beside that he was insanely fast again thanks to witcher body/training.
Sapkowski did some blunders on sword fighting but "Witcher style" of combat is believable as it simply requires body of witcher to overpower mass of moving object and speed to strike from positions and angles which are impossible for normal human. Also it is kind of interesting take on sword combat instead of hurr durr POWAH. His swordfighting in large part relied on people expectations of what human body could do with piece of metal where he was witcher and he cheated that aspect of fight.
Bullshit or not piruettes half spins and so on are his fighting style. Arguing about it being realistic is like arguing about Star Wars lightsabers combat being realistic.
And if we are talking about actual real sword fighting... reality would be like:
Dude has a sword and starts a fight. Dude is killed by spear.
Dude has a sword and starts a fight. He dies because neither lether nor plate armor is penetrated by sword.
There is a reason why Spear was battle weapon and why Sword was basically todays handgun.
Swords are only popular in todays popculture because they look good and have this (it needs skill to use it instead of bashing it like a hammer).
There is also a reason why Swords later were completely changed into rapier form making it essentially very short and light spear...
That is completely beside how swords actually worked which is almost nothing like in TV especially for longer swords which became for some reason slashing weapons in popculture where their main attack was stabbing (again like a spear).
Especially hilarious is how TV portraits main staple of medievil knight in full armor + sword and shield. If on battlefield two knights like that would meet then both of them would rather die grappling each other than using their swords which were completely useless on fbp armor.
Reality is that medieval knights wore plates because they were cavalry and they rode horses so they didn't need actually use their own body muscless to march few miles/km to battlefield. Also their primary weapon was again spear or should i say "lance".
Who is the composer this time?
The Witcher games are probably the only ones where the mocap guys knew how western swordfighting actually works. (as in - most of them are in HEMA groups)
