and it wasn't a 'cavalry unit.'<<
Like Hell there wasn't. The Pomorske Brigade (translated 'Pomeranian'

. This brigade was an elite unit in the above mentioned Pomeranian Army. On the evening of Sept 1, the 18th Lancers (a regiment of the Brigade), led by Col. Mastelarz, while in the process of mopping up a German infantry battalion, was jumped by a column of German armored cars. The horrific results of 20mm automatic cannon engaging mounted horsemen at close range was erroneously reported by Italian war correspondants as the result of a deliberate cavalry charge vs. tanks. The myth was born, and it remains to this day.
Todd