Q I couldn't find the source for this supposed anonymous chronicle.
It is in one manuscript of the the so called 'continuation of Detmar's Lübeck chronicle'. Originally a single manuscript, now in Hamburg State Library (Ms Ham Cod Hist 33). Printed source editions — as long as they are young enough to include this late find — are reliable transcriptions of ...
The first source below confirms:
that given numbers in the past may be unreliable
quotes the Lübeck Chronicle with similar numbers
As tremendous as the battle and the decision of Tannenberg was, and as much as was recorded at that time, it has only been passed down with great uncertainty.
The sequel to Detmar's Lübeck Chronicle puts the Polish-Lithuanian ...