Kingdom Come: Deliverance is ostensibly set at the beginning of the 15th century, and as such features heavily armored men at arms, knights, and various other soldiers doing battle. The arms and armor are decently represented for the period of history and setting (the Holy Roman Empire in and around the modern day Czech republic).

However, while there may be accuracy in the weapons and protection, the gameplay does oversimply (out of necessity) medieval combat simulation perhaps leading to confusion as to what a real battlefield might resemble. Like many examples of modern media, combatants in this game are shown delivering slashing blows, and stabs directly against heavily armored opponents, disregarding the protections in place. While armor was not infallible, well made 15th century armor did greatly reduce the chances of injury against attacks such as simple blows from arming swords.

This demonstration by the Le Musée National du Moyen-Âge de Cluny showcases the protective ability of well made 15th century full harness, resisting a sword blow (0:36), as well as techniques that were used specifically to overcome such defenses (starting at 1:45).

So while simple swipes of a sword or axe are unlikely to breech armored defenses, that does not render heavy infantry/horsemen invulnerable to attack. Polearms, Long twohanded swords, grappling and using daggers, half-swording, attacks from horseback with lances and other weapons at a charge all can cause serious injury or death even while in heavy harness.

Period art from the 15th century does indeed show that combat could be a bloody affair. Lastly you have this passage from Gesta Henrici Quinti (1417) which is an account from the battle of Agincourt and reads in part:

But after a short while, the enemy ranks, according to the will of God once they had tasted the bitterness of our weapons and our king had drawn close to them, abandoned to us a field of blood along with carriages and their draught- horses, many being filled with provisions, weapons, lances and bows. And thus when, on God’s orders, the strength of that people had been dissipated and the rigours of the war had finished, we who had obtained victory returned through the masses, mounds and piles of dead men, and saw and inspected them, but not without the pain and tears of many, because so many outstanding and most powerful soldiers – had only God been with them – had sought their own deaths in such a manner from us, completely against our wishes, and had thus vainly destroyed and broken up the glory and honour of their own dwelling place.