Complex sentence: Each panzer battalion totaled now 4 companies instead of 3, a 3rd company had been added to the antitank battalion, and a field replacement battalion of 3 companies had been added.
Split into simpler sentences: Each panzer battalion was comprised of 4 companies instead of 3, and a 3rd company had been added to the antitank battalion. A field replacement battalion of 3 companies had also been added.