I searched for the heraldry of the second knight, and could only find it as being the coat of arms of Krementchouk, city in Ukraine

Kremenchuk was supposedly founded in 1571.
The name Kremenchuk is explained as deriving from the word "kremen" -
(a mineral) because the city is located on a giant chert plate. An alternative explanation says that "Kremenchuk" is the Turkish for "small fortress".
However this fortress appeared to have been built only in 1571 by Sigmund II, king of Poland?
Therefore it is highly improbable that a knight of the XII-XIIth century would have been involved in a tournament in Bavaria with a coat of arms above "Azure a fess argent" as painted below….
Therefore I will look for another coat of arms if that second knight will be painted by the first one; for a knight living in the same period and neighbourhood…..