Ok, so from a historical perspective, a guy from Mali - a DOCTOR even - traveling to Bohemia during the late middle ages makes absolutely zero sense.
The Malians weren't known to be great travelers. The one major expedition we know of is when king Mansa Musa went on pilgrimage to Mecca and brought so much gold with him he caused inflation in every town he passed through lmao. Other than that, Malian traders didn't venture that far. Timbuktu was a local trading center but it was usually Arab and North African merchants going there, instead of Malians spreading out. It was a Muslim kingdom so some of its population went on pilgrimage to Mecca occasionally, which is the main source of contact between Malians and the rest of the world during the middle ages. We know about Malian history primarily from Moroccan and Andalusian muslim historians who decided to travel to that country and describe it.
And the Muslim historians of the time all agree that Malian medicine is horrible. If you end up sick in that area, it's a better idea to just pray to Allah instead of going to a doctor, because their medicine is worse than useless. So having a Malian doctor travel to Bohemia makes absolutely zero sense. Why would he even be going there in the first place? Why Bohemia of all places? A Muslim scholar traveling to the Latin Christian world wouldn't be too out of place, but he'd probably go to Italy instead, not some provincial backwater in central Europe. Maybe London or Paris.
Also, a Muslim scholar traveling to Europe would either be Andalusian, Berber, Arab, or Persian. Not Malian. They didn't even write down their own history, that was done by scholars from the whiter areas of the Muslim world.
If they wanted a black character, they could have taken an Ethiopian. Ethiopia was a Christian realm at the time, and an Ethiopian might have ended up in Byzantium for some reason, and from there he could easily have traveled to Eastern Europe. There would be a convincing, believable itinerary for an Ethopian scholar. Up the Nile river, then to Byzantium by boat, from there to Bohemia.
But they chose a Malian. There is no historical reason, nor any narrative reason, for choosing a Malian in particular.
The only reason to choose a Malian is because Mali was the biggest west African empire at the time. And African Americans are descended from west African stock - can't take an Ethiopian, because they are of east African stock and have a completely different physiognomy.
They chose a Malian because they wanted to represent African Americans.
That is the one and only reason why you would put a Malian into 14th-15th century Bohemia.