Complex sentence: By this stage in the war the Tank Corps had suffered greatly and there were fewer tanks available for the battle than had been deployed in the Battle of Amiens in August, and the September 29th attack would highlight the vulnerability of tanks to strong German anti-tank measures.
Split into simpler sentences: By this stage in the war the Tank Corps had suffered greatly and there were fewer tanks available for the battle than had been deployed in the Battle of Amiens in August. The September 29th attack would highlight the vulnerability of tanks to strong German anti-tank measures.