Complex sentence: The Wehrmacht fielded Army Group Centre's 2nd Panzer Group and the 3rd Panzer Group and the Red Army fielded the Western Front, the Soviet Reserve Front, the Soviet Central Front, and the Soviet Bryansk Front.
Split into simpler sentences: The Wehrmacht fielded Army Group Centre's 2nd Panzer Group and the 3rd Panzer Group. The Red Army fielded the Western Front, Reserve Front, Central Front, and Bryansk Front.