This movie is a whole mess, a total wrong doing.
Lack of historical facts, lack of historical authenticity ( except that koreans were, and still are, so stupid that they didn't know any formation. In 1636.
This is one of the reason why Qing Dynasty dignified ruled in Korea, with a rightful conquest. In history, korea pretended to struggle, because they lacked any proper war tactics and techniques.
The movies shows that the fortress was an helpless way to struggle ( i would have preferred to show the General who fought after the King surrendered, to see Huang Taiji forgiving him and sending him back without any harm).
The King kneeling towards the rightful and good Great Qing could only be the only outcome.
They only accept their destiny of slaves, and it's not even nationalism of pride, it's even inferior that the ""Barbarians"" they fought, showing the real Barbarians is Korea itself.
And obviously, always cheering for our Great Qing.