A plot hook from me...
The PCs receive a radio signal from someone purporting to be the CO of 11th Infantry Regiment, "The Wandering 11th" (10th Infantry Brigade, 5th Infantry Division). He is requesting all friendly forces in the area that receive his signal to make their way to a grid reference 10 clicks southeast of Milicz (to the west of Kalisz), where he promises he will regroup for a concerted drive westward to the German border. If the PCs take the CO up on this offer they will have to fight through several dozen clicks of terrain patrolled by remnants of the 3rd Guards Spetsnaz Brigade (now about company strength, mostly on foot), some of OPFOR's best troops. When they finally link up with this CO however they soon learn that he is a low ranking Corporal who has promoted himself to nominal CO of the 11th under some delusion that he can win the war, and he is in fact going to counter-attack towards Kalisz rather than head for the German border. If the PCs refuse to go along with his hairbrained scheme, he will turn on them as deserters and attempt to capture or kill them to steal their gear.
Now make the Corporal a Jaded Professional trope, who was a young corporate upper management whose sky rocketing career was interrupted when he was drafted, but was denied a commission because of some psych eval. "I should have been a colonel. They just don't understand me!"