You need to do some research on penal battalions. Alot of the soldiers in the battalions were soldiers who had been encircled earlier in the war. Alot of trained officers had been sent to the penal battalions also. If anything the penal battalions had some of the most trained soldiers around.
look up a book called penalty strike on google. Read some of the free pages. Penal Battalions were used before attacks to infiltrate and break through enemy defenses. Get behind enemy lines and sabatoge communications and logistics.
Penal battalions were given flame throwers, ppsh lmgs and other various weapons. They were however only given these weapons right before they were about to go on a mission.
Yes? I know Penals were used as frontline shock troops, when they weren't just put into suicide squads or used as disposable cannon fodder. So why do they have long-ranged SVT40s? PPShs would fit their role far more. This isn't about precise realism, but about giving the Penals a reason to exist. Right now they have next to none.