Complex sentence: The Sixth Army needed 700--800 tons each day, with food and munitions as top priority, but they received only a fraction of that, and some deliveries such as spices and summer clothing were completely useless to the troops.
Split into simpler sentences: The Sixth Army needed 700--800 tons each day, with food and munitions as top priority, but they received only a fraction of that. Some deliveries such as spices and summer clothing were completely useless to the troops.