Complex sentence: These units had an organic strength of about 1,200 tanks and the Panzer divisions were very vulnerable again, the mechanical condition of their tanks rapidly deteriorating but the condition of the Allied divisions was far worse.
Split into simpler sentences: These units had an organic strength of about 1200 tanks and the Panzer divisions were very vulnerable again, the mechanical condition of their tanks rapidly deteriorating. But the condition of the Allied divisions was far worse.