The situation was exactly as the commander of the Polish Second Army Group had anticipated; after several days of meticulous preparation, once they had confirmed that the main Polish forces were tied down on the western front, the German First Army Group immediately launched their blitzkrieg plan against Poland.
To accomplish this lightning strike, Germany committed all of their armored troops and motorized units.
This included 3 tank divisions, 3 motorized infantry divisions, 5 light armored divisions, and 2 cavalry divisions. To supplement and support their firepower, the East Prussia region, where the First Army Group was stationed, also had more than 1,200 airplanes and 2,400 firearms at their disposal.
In contrast, the Polish Second Army Group had 4 infantry divisions, 4 cavalry divisions, 1 tank division, and 3 artillery divisions.