I don’t consider myself an avid historian of Slavic exchanges historically but at least from everything I know it’s patently absurd to somehow implant a Mali Muslim into the service of a king who was directly involved in the crusades against the Ottoman Empire. From Varva:

6/10 The game takes place in one of the richest cities in Europe which was besieged by a massive foreign army. That´s the reason why the life in such a city is more diverse than the life in villages which were featured in the first game. 7/10 Musa came to Bohemia with an invading army as a member of the royal court of King Sigismund, whom he met thanks to his engagement at the court of Sultan Bayezid. He's an educated noble and renaissance man from the Kingdom of Mali.

So King Sigismund, a Hapsburg and king of Hungary, who was at war with bohemian Hussites (heretics) and was fighting a religious war supposedly hired a black Muslim retainer from an engagement with a sultan… who was already and repeatedly at war with the king and trying to take his claims in Hungary. Not only this but Sigismund was repeatedly engaged in the crusades against the ottomans and was notorious for fighting “heretics” and advancing Catholicism. How is any of that supposed to make sense?