Complex sentence: The advanced guard suffered many casualties and retreated to Warlus and German tanks counter-attacked Warlus and Duisans and were repulsed but managed to cut the road between the villages and the Right Column was unable to advance further.
Split into simpler sentences: The advanced guard suffered many casualties, retreated to Warlus and German tanks counter-attacked Warlus and Duisans. The German attacks were repulsed but managed to cut the road between the villages and the Right Column was unable to advance further.