Complex sentence: The 5th Army in the north was in better shape, had the protection of the Pripet marshes to its rear and still had 3 Mechanised Corps under command, and using these lunged southward cutting the supply road behind the panzer spearheads.
Split into simpler sentences: The 5th Army in the north was in better shape, had the protection of the Pripet marshes to its rear and still had 3 Mechanised Corps under command. Using these it lunged southward cutting the supply road behind the panzer spearheads.