Complex sentence: The Italian armored regiments were from the 133 Armoured Division Littorio and included between 150 to 250 L3/35 tankettes which were little more than lightly armored machine-gun carriers not suited for modern warfare.
Split into simpler sentences: The Italian armored regiments were from the 133 Armoured Division Littorio and included between 150 to 250 L3/35 tanks each. But these vehicles were often classified as "tankettes" and were little more than lightly armored machine-gun carriers not suited for modern warfare.