In an Arthurian setting, Hans's ancestry follows that of LibuΕ‘e, who will be a stand in for EliΕ‘ka, and PΕemysl and the seven Bohemian mythical princes as documented in Chronica Boemorum: Hans is the great grandchild of EliΕ‘ka (LibuΕ‘e) and PΕemysl (Capon), the grandchild of the first prince ΔenΔk (Nezamysl), and the child of the second prince Jeschke (Mnata). The third prince is Vojen, Mnata's son, who I reckon would be Hans, though I'll spell the name as Vojan (pronounced voy-yahn) for the Hans / Jan diminutive. And as Vojen's son is Vnislav and Vnislav is the described as the fourth prince, Vnislav would then be Hynce. And as Hynce has a daughter named Marketa, the line then continues through her husband Victor's name (KΕesomysl), and then through their son Neklan (though they also have a daughter, and only a daughter in canon, by the name of Johanna.)
Since Hanush isn't in the line of succession, as it passes from first born son to first born son and Hanush is the youngest child and the second born son of ΔenΔk (Nezamysl), Hanush is, well, Hanush, though Hanush still stands as Regent Prince / Regent Lord as Jeschke (Mnata) dies in Hans's youth. The story follows canon, with Hans instead the Prince of Pirkstein and Rattay, except Hans flees to Prydain and Camelot to become a knight in King Arthur's court as Sir Vojan, or Sir Hans / Sir Jan, seeking a life of adventure and chivalry rather than of politics and princehood.
In the canon Arthurian timeline, Hans's son is still sired by Henry, either a Bohemian commoner or a Prydain commoner who, too, sought to serve King Arthur β think along the lines of Lancelot and Galehaut. Relationship permitting, though, in another timeline, Hynce is the son of Hans and someone else, but Hynce remains an important and necessary addition to the story, a la Lancelot and Galahad.